Rochester Institute of Technology
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Theses
Thesis/Dissertation Collections
1989
COACH: A two level expert planning assistant for
high school football
Gary F. Hasman
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Recommended Citation
Rochester Institute of Technology
School of Computer Science and Information Technology
COACH
A TWO LEVEL EXPERT PLANNING ASSISTANT
FOR HIGH SCHOOL FOOTBALL
by
Gary F. Hasman
A thesis submitted to
The Faculty of the School of Computer Science and Information Technology
in
partial fulfillment of the requirements for the degree of
Master of Science
in
Computer Science
Approved by:
John A. Biles
william McAlee
Title of Thesis:
COACH
A Two Level Expert Planning Assistant
for High School Football
I, Gary F. Hasman, _
_
_
hereby grant permission to the Wallace Memorial Library, of R.I.T., to
reproduce my thesis in whole or in part. Any reproduction will not be used
for commercial use or profit.
TABLE OF CONTENTS
i. Abstract
ii. Acknowledgements
1. Introduction and Overview 1
2. Background 4
2.1. The Game of Football 4
2.1.1. General Concepts 4
2.1.2. Offensive
Strategy
72.1.2.1. The Game Plan 7
2.1.2.2. Player Personnel 8
2.1.2.3.
Play
Selection 82.1.3. The Playbook 9
2.2. The Computer in Football 10
2.2.1. Statistical Analysis 10
2.2.2. Beyond Statistics 10
2.3. Expert Systems in the
Planning
Process 112.3.1. An Introduction to
Planning
112.3.1.1. The Corporate Environment 12
2.3.1.1.1. Strategic
Planning
122.3.1.1.2. Tactical
Planning
152.3.1.2. The
Military
Environment 162.3.1.2.1. Strategic
Planning
162.3.1.2.1. Tactical
Planning
182.3.1.3. Some Additional Comments on Planning... 20
2.3.3.
Planning
in Football 322.3.3.1. Strategic Football 32
2.3.3.2. Tactical Football 35
2.3.3.3.
Using
the Computer 363. Project Description 38
3.1. Design Overview 38
3.1.1. What COACH Does 38
3.1.2.
Keeping
Things Reasonable 393.2. The Expert 40
3.3. The Files 41
3.3.1. The Opponent File 41
3.3.2. The Player Comparison File 43
3.3.3. The Game Plan 44
3.3.4. The Rule Base 45
3.3.5. The Data Files 45
3.3.6. The C Code Files 46
3.4. Implementation 47
3.4.1. The Hardware 47
3.4.2. The Software 47
3.4.2.1. RuleMaster 47
3.4.2.2. Turbo C 49
3.4.3. System Creation 49
3.4.3.1. Game Plan Creation 49
3.4.3.2.
Play
Selection 523.5.
Testing
544 . Conclusions and Future Enhancements 55
4.2.
Play
Selection 554.3. Overall Conclusions 55
4.4. Future Enhancements 56
5.
Bibliography
576. Appendices 69
6.1. Football
Terminology
696.2. Defensive and Offensive Alignments 70
6.3.
Play
List 836.4. Strategic Level Samples 84
6.4.1. Sample for the 5-3 Defense 85
6.4.1.1. Inputs 85
6.4.1.2. Outputs Generated 86
6.4.2. Sample for the 5-2 Defense 87
6.4.2.1. Inputs 87
6.4.2.2. Outputs Generated 88
6.4.3. Sample for the 4-4 Defense 89
6.4.3.1. Inputs 89
6.4.3.2. Outputs Generated 90
6.5. Tactical Level Samples 91
6.5.1. Standard Inputs 91
6.5.2. Outputs Generated 92
6.5.2.1. Against the 5-3 Defense 92
6.5.2.2. Against the 5-2 Defense 93
ABSTRACT
This thesis describes a two level expert planning system that first helps to
develop
a game plan for a high school football game and then aids in the selection of playsduring
that game. Built usingRulemaster,
an expert system developmenttool,
the system, calledCOACH,
isinitially
provided observed data through the answering of questions which represents the receiving of a scouting report. This information is stored in a data file for further use. Also
created
during
this questioning period is a data file containing comparisons ofkey
players on the offense against their counterparts on the opponent's defensive team.Using
a rule base established from interviews with an expert football coach, COACH creates a constraintfile,
the game plan, which is usedduring
the play selection portion of the programming.During
this phase, COACH is provided the current game situation and subsequently selects one or more plays from the game plan deemed mostlikely
to besuccessful.
ACKNOWLEDGEMENTS
IBM PC is a registered trademark of International Business Machines Inc.
RuleMaster is a registered trademark of Radian Corporation.
Turbo C is a registered trademark of Borland International Inc.
Microline 92 is a registered trademark of Oki America Inc.
1. Introduction and Overview.
The field of artificial intelligence is slowly creeping into every facet of our
daily
lives. We have seen itinsert itself into medical, military, and industrial settings. The use of artificial
intelligence,
inparticular expert systems, to solve everyday problems is
definitely
on the rise. Artificial intelligence was first demonstrated in the realm of game playing, where strategywas defined as the selection of the best choice from among many. The game of chess was the focus of the initial
thrusts,
with checkers,backgammon,
go-moku, and the like not far behind.While these games involve strategy,
they
are concerned with pre-definition of the search spacebecause,
while the number of possible moves from a given situation is great, it is finite. Also, these moves can be the same ones thatwould occur repeatedly given a particular state of the game board.
Introducing
dynamic factors into the game, such as different strength pieces of the sametype,
or a boardsituation that could change while the next move is
being
considered, would seriously confound the established paradigms for playing the gamesby
computer.The game of
football,
at any level of play, has these dynamic factors. Additionally, while the basic situationof a game may be relatively consistent from game to game, the personalities of both the players and the coaches have
a definite influence on the outcome of any particular play.
This thesis looks at two levels of planning within the confines of the game of football. At the strategic
level,
a game plan is developedby
the coaching staff afterlooking
at weekly scouting reports. This game plan is a list of plays that are deemed potentially successful against this week's opponent. It is carried into the game, and from it each play is selected as the game progresses. This singleplay selection represents the second level of planning, the tactical level.
The strategic level is enacted through a question and answer session that elicits the same information found in a scouting report. This information is then used
by
the expert system to create a series of files that represent the various sections of the game plan. Also created at this level is the player comparisonfile,
which provides aThe tactical level is enacted through a rule-based expert
system, which uses the game plan
files,
the playercomparison
file,
and user input.Here,
the user is asked to provide information on the current game situation to allowthe expert system to refine its search for the proper play.
At the end of each game plan creation or play selection,
the user is prompted for continuation of the current
session or for termination and return to the next higher
level of the system. At the
top
level,
guitting the system is one of the user's options.Chapter 1 of this paper provides a short introduction of
the entire project. It includes a brief overview of what the project entails and a chapter-by-chapter summary of
the paper.
Chapter 2 covers the background necessary to understand
what the project is doing. Include here is a short
introduction to the game of football with
basic*
information on the offense, the
defense,
and the coach'sgeneral preparation before each game. In the section on
the computer's use in
football,
a short description of aprofessional football team's use of statistics is
discussed. This is followed
by
an introduction to theplanning process in two different environments; the corporate and the military. Next several computer-based
planning systems are reviewed in an effort to formulate the requirements for the planning system of this paper.
Finally, this chapter concludes with the extension of the discussion on planning into the game of football.
Chapter 3 describes the computer program
(COACH)
that wasimplemented. Include is what the program
does,
and does not do and what limitations were imposed and the reasoning behind them. A description of the files used and generated,an introduction to the software used, the creation of the
system, and the
testing
process are also covered in thischapter .
Chapter 4 summarizes the project. It discusses the overall
success of the project in terms of goal achievement and
practicality. Also mentioned are the shortcomings of the
final program and some proposals for future improvements.
Chapter 5 contains the
bibliography
for the researchportion of this paper.
Chapter 6 contains the appendices. Here is found a short
play
selection. Here too, are the input data for thetesting
of theprogramming
at both the strategic and the2.
Background.
2.1. The Game
ofFootball.
2.1.1. General Concepts.
A
football
gameis
a seriesof strategic and tactical moves and countermovesbetween
twoopposing
teams who areusually
coachedby
experiencedindi
viduals.
The
gameis
playedin
a restricted space called theplaying
field
(Figure
1). Within the confines oftheplaying
field,
movementis
unrestrictedlaterally
and vertically.THE PLAYING FIELD
0
10
20
30
40
50
40
30
20
10
0
END ZONE
END ZONE
FIELDIS 120YARDS LONGAND 160 FEETWIDE. HASH MARKS ARE53FT,4 IN. FROMTHE SIDELINES
The
coacheshave
attheircommand a cadre ofplayer personnelwho make upthe various parts of the team.
These
partsinclude
the offensive unit, thedefensive
unit, and the special units such as thekickoff,
return, and puntunits.
Each
ofthese parts,when on thefield,
have
1 1 players.Some
of theplayers
may
participate on more than one ofthedifferent
units. In additionto the 11 on the
field,
there areusually
replacement personnel on thesidelines
during
the gamein
case ofinjuries
or other reasonfor
inability
toplay.
The
offensive portion ofthe teamis
led
by
the quarterback, who putsthe coach's plans
into
effect.It
is
the offense'sjob
to advance theball
down
the
playing
field
with theintention
ofscoring
pointsagainsttheiropponents.This is
done
by
repeatedly moving
theball
atleast
10 yardsin
four
attemptsuntil the end zone
is
reached. If the end zoneis
not attained, then afield
goal
may be
used to score, theball may
be kicked
away
to the opponents, orthe
ball
may
be
given overto the opponentsatthe point offailure
to attainthe
necessary
yardage. Astandard offensive alignmentis
shownin Figure
2.STANDARD
T
FORMATIONQUARTERBACK
HALFBACK
^j
f~J
C
J
END TACKLE GUARD CENTER GUARD TACKLE END
OOO
O
OOO
O
HALFBACK
FULLBACK
FIGURE
2
STANDARD 5-3
DEFENSE
H
S
H
B
B
B
VV
V
VV
A
oooeoooif
o
DIRECTIONOF PLAY
T7= LINEMAN B = LINEBACKER H = HALFBACK S = SAFETY
FIGURE
3
The
defensive
squad(Figure
3)
is
responsiblefor
preventing
the opponent'soffensive unit
from
scoring. It mustbe
able to guess the opponent'sintentions
on each of thedowns
and reactaccordingly
toimpede
theirprogress.
The
kicking
unitis
used tokick
theball
to the opponents at thebeginning
ofeachhalf
ofplay
and afterany scoring
event.The
return unitis
used to catch the opponent's
kickoffs
or punts and return theball
asfar
aspossible
before
being
tackled. Thepunting
unitis
theonethatkicks
theball
to theopponents whentheoffense
has failed
to makethe required yardsfor
2.1.2. Offensive Strategy.
Because
this thesiswillbe
concerned withplay
selection,only
the offensivepartofthe gamewill
be
considered.To
that end, theformulation
ofgeneraloffensive
strategy
ofa coach will nowbe discussed.
2.1.2.1. The Game Plan.
Before
any
gamehas
started, thecoaching
staff plansits strategy
for
theupcoming
opponent.One
or more members of the staff will attend theopponent's games and make notes about that opponent's
play
of thosegames.
These scouting
reports are then studied anddiscussed
toformulate
an overallgame plan
forthe
upcominggame.The
game planis
simply
alist
of offensive playsthat thecoaching
stafffeels
will prove successful in
gaining
yardage against the scouted opponent.The
game plan sets the overall tone of
how
the opponent willbe
attacked andwhere that attack will take place. If all goes well, the game plan can
be
followed
quite closely.If,
however,
the opponenthas
made significantchangesto
his defensive
strategy, the game planmay
be
abandonedin
part2.1.2.2.
Player
Personnel.
The
coach must notonly
know his
opponenttodetermine
thebest
offensivestrategy,
but he
must alsoknow his
own team'sabilities and capabilities.The
coach must
be
keenly
aware ofhis
players'
strengths and weaknesses.
Does
thequarterbackthrow
better
whilemoving
tohis
rightortohis
left
? Canhis
righttackle
block better
to the outsideorto theinside
?These
types of questions are answeredfor every
player on the team.The
coachthen matches
his
players againsttheirexpected opponent on aone-to-one
basis.
This enables the coach todetermine
thelikelihood
ofhis
playerbeing
abletocontrolhis
opponentduring
thegame.It is
thiscontrolthatwilleventually
determine
theoutcome ofthe game.2.1.2.3.
Play
Selection.
Armedwiththeabove
information,
thecoachleads
his
team ontotheplaying
field.
As the game progresses, the coach will select playsbased
on thisinformation aswell as
factors
thatare presentatthetime ofselection.These
additional constraints can
include,
but
are notlimited
to,
quarter ofplay, theopponent's
defensive
arrangement,down,
yardstogo,and playerinjuries.
Not all these
factors
are relevant onevery
play.The
dynamics
of the gameof a
few factors
which, when combined with thescouting
report and theplayer comparison chart,
determines
whichplay
to select.It
shouldbe
remembered that the coach can control some ofthesefactors.
However,
thereare somehe
cannot.The
extentof controlhe has
is generally
not
important,
but
the coach'sability
to manage the effect ofthesefactors
on
his team,
and the game,is.
2.1.3. The Playbook.
As mentioned, the game plan
is
alist
ofoffensive plays selectedby
the coachand
his
staff ashaving
the greatest potentialfor
success against this week'sopponent.
But
wheredo
these playscomefrom
?Over theyearsthe coach and
his
assistantshave
studied successful teams andselected plays
from
their repertoires. The coachhas
then either used theplays outright, or modified them to
fit his
teams'capabilities.
Additionally,
he
andhis
peoplehave
designed
theirown plays. These playsweredrawn
upto
fit
the particular abilities ofkey
players on the current squad. All theseplays
may
be
writtendown
in
a playbook orsimply
kept
mentally. As theseasons progressthis playbook
is constantly
revised and updated with new,better,
orjust different
playsin
ordertokeep
opponentsfrom
being
able to2.2. The Computer
in
Football.
2.2.1. Statistical Analysis.
David
Coursey
in
theOctober
12,
1987 edition of MISWEEK[Coursey
87]
indicated
that theDallas Cowboys
of the National Football League(NFL)
enter
every
offensiveplay
anddefensive
alignment ofthe seasoninto
theirmainframe computer.
The coaching
staffthen examines"hundreds
of pagesof
detailed
analysis"
and selectsthe playsmost
likely
tosucceedin
thecoming
game.
They
can alsoquery
the system and obtain answersto questionssuchas
"Who
are theRedskins
(another
NFL
team)
likely
to passto on thirddown
with
long
yardage?".This
systemis
apurely
statistical analysis of pastperformances,
but
at thishigh
level
of play, theconsistency
of each team'sstyle
lends
itself
tostatistical analysisand alsoto predictability.2.2.2. Beyond Statistics.
These
statistics providedata before
thegamebegins
and areactually
ahighly
sophisticated
scouting
report. While statistics canbe
ofvalue,however,
they
leave
outmany
factors
important
to the game,especially
those that appearduring
the game.The
personality ofthe coach could provide the exceptionto the rulewhen warranted
by
thesituation. Aninjury
to akey
player pickedby
thestatistical approach couldlead
to a nonstatistical playerbeing
selectedto
handle
thefootball.
Thesekinds
offactors
force
the analystaway from
theAn expert system could
insert
thiskind
ofinformation into
thedecision
making
process and, as a result,lead
tobetter play
selection at the time ofthe play, ratherthan
before
the gamebegan.
2.3. Expert Systems
in
the
Planning
Process.
2.3.1. An Introduction
to
Planning.
In
its
mostbasic
form,
planning is simply
theestablishing
of a course ofactionthat
is
designed
to reach some end resultin
afavorable
manner.Planning
is
usedby
thehousewife
todo
theshopping
atlocal
stores,by
Fortune 500
executives to control their particular part of the
business
world,by
generalsto win wars,
by
governments to win orkeep
allies, andby
coaches to winfootball
games.Planning
occurs on threegenerally
acceptedlevels:
strategic,tactical,
and operational. Atthe strategiclevel,
the overall objectiveis
established and themeans to gain that objective are
delineated.
For theindustrial
setting, this objectiveis
usually toincrease
the general net worth of the corporation[Bogue
86].
For
themilitary
commander,it is
generally
the employment offorce
andmilitary
resources to conquer some piece of physicalterritory
[Cushman
86,
Peacock 84]. Forthefootball
coachit isto
winthenext game.At the tactical
level,
corporations take management action to achieve thechanges required
by
the strategic plan[Fry
86,
Tourangeau
81]. In
the militafootball,
the tacticallevel involves
selecting
the nextplay
to counter theexpected
defense
putforth
by
the opponent.The
operationallevel
is
concerned with theday-to-day
nuts andbolts
execution of thepreviously
decided
strategy
and tactics[Espy
86]. This
correspondstotheindividual
worker, soldier, or playerlevel
ofthe respective organization.2.3.1.1. Corporate Environment.
In
corporateAmerica,
each company,large
orsmall, mustmap
out whereit is
going in its
line
ofbusiness
andhow it intends
to get thereif
thatcompany
expectsto
have
any
future
success, orany
future,
for
that matter.Numerous
books have been
writtendescribing
theplanning
process,both
in
theory
andin
practice.We
will examine thebasics
of corporateplanning
to provide afoundation
for
further
discussion.
2.3.1.1.1.
Strategic
Planning.
As
previously
mentioned,the main objective ofthestrategicplanning
processin
business is
to improve the economic value ofthe company. Afteragreeing
on this point, authors go on to point out that the
planning
process also[Steiner
69],
identify
past andprevailing
strategies[Fry
86],
anddevelop
ideas
and conceptsthatwill guidethe
company
oversome period oftime[Espy
86].
If
these things aredone
correctly,
the entire process would,according
to[Ewing
68],
...leadtoa
better
position orstanding for
theorganization...help the organizationprogress in the waysthat
its
management considers most suitable...help
keep
theorganizationflexible
...indicate to management
how
to evaluateand check up onprogress towardplanned objectives[Crego
86]
supportsthiscontention and continuesit
by
saying
that...inaddition toproviding a
logical
and rationalsense ofdirection
for
the organization, a[well
thoughtout]plan...can
identify
strengths and weaknesses ofthefirm
...can
identify
potential problemareas...coordinateand ensureconsistency
in
theplans of variousunitsor
divisions
[of
the company]...establisha
framework
for
making
key
decisions
in
theongoing
managementprocessTo
accomplish allthis,
many
hours
ofstudy
must gointo
theplanning
process.They
must examine the current state of theindustry.
They
need tobecome
deeply
familiar
with theircompetitors.Self
examination requires management to analyze,in
depth,
its internal
strengths and weaknesses
[Hind
83].
These
can reveal whether or not previous
planning has
recognized and set strategic goalssoundly
[Ewing
68].
By
knowing
thelimitations
ofthe company, executives can plan waysto expandthese
limits.
By
recognizing
the thingsit
does
well, thecompany
can move to takebetter
advantage of these strengths.This
analysis can alsodetermine
whether these strengths and weaknesses are real or artificial.
Subsequent
planning
canremedy inconsistencies
and provide an overallstrengthening
ofthe organization.
Examining
the state of theindustry
andits
markets will reveal those areas where more effortis
required. This ,in
turn,
will generate themarketing
strategy
portion of the overall strategic plan and will showcompany
managerswhere additional opportunities existon whichtocapitalize
[Espy
86].
Nearly
every
author addressed the needfor
management tobecome
very
knowledgeable
about the competition in their segment of thebusiness
world. Because
every
competitoris
different
in its internal
structure , andtherefore,
in its strategy in
the marketplace, eachhave
inherently
different
strengths and weaknesses
[Bogue
86].
It
is imperative
that each competitora
business
strategy
anchoredin
anobsoleteunderstanding
ofthecompetitive situation and the
key
factors
thatdrive
it
is
a ticket tostagnation and slow
decline.
2.3.1.1.2. Tactical Planning.
Tactical planning
is the nextlevel down
in thehierarchy
of planning.Essentially,
it
deals
with the moreimmediate
objectives ofthecompany
andhas
asignificantly
more restricted time span[Tourangeau
81].
Once
thecorporate
strategy
has been
defined,
each subdivision of thecompany
must generate plans ofits
own to accomplish their portion ofthe overallcompany
objectives.These
plans willdelineate
the sequence of actionsnecessary
toimplement
the company'sstrategy
[Sackman
72].[Glaser
75]
suggests that tacticalplanning
is
more practical than strategicplanning
andclosely
correspondsto allocative planning, which
is
concerned with thedistribution
ofavailable resourcesamong
competing users withinthecompany.A good
strategy
does
not guarantee good tactics. Infact,
according
to[Bogue
86]
given aspecificstrategiccourse, the result
is
likely
tobe only
asgoodas the implementation.
The
implementation referencedis
that providedby
the tactical plan.The
success of this implementation will
depend
on management'sability
tolevels.
This
implies
notonly
good communication skills,but
the communication of corporate objectives that at
least
appear to parallel the objectives ofthe employees
[Tourangeau
81].
This
cohesiveness of purposeis
critical toany
organization's continued success.2.3.1.2. The
Military
Environment.
The military
establishmenthas,
of course, usedplanning for
centuries.Whether
around aMongol
campfire orin
aPentagon
conference room,military
leaders
have
established goals or objectivesfor
their respectivearmies and
devised
meansfor achieving
thosegoals.These
methods ofplanning
have been
revised and refined over those samecenturies to the extent that most
military
organizations send their officerpersonnel to schools to
learn
those methods. At these staff collegesthey
study
Pericles, Clausewitz,
SunTzu,
andmany
otherstolearn,
notonly
how
togive orders,
but how
todecide
which orders to give. In simplerterms,
they
learn
to plan.2.3.1.2.1.
Strategic
planning.In
many
ofthebooks
readin
preparationfor
this paper,numerous referenceswere made to the
fact
that after years of neglect, corporations werebeginning
to pattern their planning activities after the military's.However,
"military
planning
is
similar to corporateplanning."
Others
see corporateplanning
asfollowing
thetraditions
establishedby
the military.In
fact,
William E. Peacock's Corporate Combat
[Peacock
84]
is
a guidebookfor
chiefexecutive officersto
follow
in
theireffort towinthe corporatewars.Peacock
maintains that corporations can pattern theirstrategy
on themilitary
because
the objectives of each are similar.Where
themilitary
seeks to gain physicalterritory,
thecompany
is seeking
to gain sales outlets and other markets.This
points outthe maindifference between
corporatestrategy
andmilitary
strategy. In the
military
planning
process the term "target"is
prevalent.While
this termhas
creptinto
corporate conversations, the connotation to themilitary
mindis
one of conquestby
force
of arms.This
leads
to astrategy
that canbe defined
as the process ofgetting
forces
onto thebattlefield,
the"where
and what ofwar"
[Cushman
86].
Cushman goes on to statethat,
therefore,
strategicplanning involves
...the
setting
ofgoals, theorganizing
offorces,
theordering
ofcampaigns, the developmentandperfection of operational
andtacticalconcepts.
When all
is
said anddone,
themilitary planning
processinvolves
stepsvery
must analyze the target and the
surrounding
terrain todetermine
thebest
approach to the goal. And
finally
he
mustfully
understand theenemy
whetherthrough the use of
direct
observation orthrough the useof accurateintelligence.
Knowing
allthis,
themilitary
commandermay
then "see opportunities andthreats in the
future
and, respectively, exploit or combat them as the casemay
be"[Steiner
69]. With properplanning
he
can"diminish
thepossibility
ofresistance...
by
exploiting
... movement andsurprise"
[Liddell
Hart 67].
In all,
he
will causehis
operational subordinates todevelop
proper tacticsthrough
clearly
communicated objectives that allow them to take aline
ofoperationthatofferssufficient alternatives so astoguarantee success.
2.3.1.2.2. Tactical Planning.
Military
tacticalplanning
involvesthe"formulationofspecific, concretegoalsandobjectives...
[and]
...thedevelopmentof specificmeans
for achieving
the[previously
defined]
strategy"
[Espy
86]
The
tactics generatedbecome
the application ofstrategy
at alower
planeAs with corporate
tactics,
resource allocation plays a major rolein
thedevelopment
of successfulmilitary
tactics. As we shall see, thisbecomes
themajor constraint when
determining
what to attack,how
to attackit,
andwith what
forces.
[Cushman
86]
notes that as within the corporate arena,"if
tactical competence
is
notthere,
any
operational schemeis in
jeopardy
regardless ofits
conceptual
excellence."
So we again see that good
strategy
does
notguarantee goodtactics.
One
area open todiscussion
is
the needfor
theindividual
soldierto see, andagree with, the overall objectives of
his
superiors.This
becomes
increasingly
controversial
because
of thevery
nature of the military.Decision
making is
mostly
a unilateral,downward flow
ofinformation in
which theindividual
soldier
has little
say.In
war,thediscussion-of
thewhy
of a particular event oraction could cause the
loss
of some strategic or tactical advantagein
time,
position, or
force.
In peacetimethismay
have
noimmediate
effect,but
couldlead
to improper expectationsin
the next conflict.Additionally,
adisgruntled
soldiermay
notfeel
obligated todivulge
information
of possiblevalue
if
he feels
putoutby
theplanning
process.In
the corporate wars,"those
employees closestto the competition... arebest
positionedtopick up thegradualorsudden shift
in
thetactical...
details
thatforeshadow
strategicchange"
On
thebattlefield,
the personnel closestto theenemy
would mostlikely
have
the
best
idea
astowhattheenemy
is
abouttodo.
In
both
cases,"without
the activeinput
andfeedback
of these experiencedcollectors
[of
information]
... animportant
window on competitors[is
lost]"
[King
86]. This
means that one of amilitary
commander'shigher
prioritiesis
the morale of
his
personnel and that good communicationsis
thekey
toachieving
thatpriority.2.3.1
.3.Some Additional Comments
onPlanning.
Before
continuing,it
may be
wise tolook
at two other aspects of planning.First
welook
at someof the things thatplanning is
not.Then
we'lllook
at avery important
attribute of planning.Many
authors, while notexactly claiming
so,leave
theimpression
thatplanning
canbe
a panacea to an organization'sills.
In orderto combatthismisinterpretation of planning's place
in
the corporatelife
cycle, several otherauthors goto greatpainstoelucidatethe things
planning is
not.[Steiner
69]
declares
thatplanning is
notforecasting. It
does
not predict consequences. Rather
it develops
a path tofollow
which,if
nothing
changes,willresult
in
attainment of a particular goal. He goes on to state thatplanning
blueprint for
thefuture.
[Ewing
68]
concurs withSteiner
and adds that"planning
is
notnecessarily
an attempttoimprove
operating
efficiency".All this
leads
to the second point:planning is
dynamic
[King
86].
It is
acontinuous process
[Steiner
69]
which shouldbe
reviewed and revised on aregular
basis [Taylor
83].
No
plan canbe,
nor shouldbe,
expected tobe feasible forever.
If the plancontains sufficient alternative routes to
follow
when conditions warrant,then
it may
requireless
frequent
changing.On
the otherhand,
narrowly
designed
plans mustbe
revisedin
theface
of newinformation
or theorganization can expect
difficult
times untilnecessary
changes areactually
made.
2.3.2.
Computers
in
the
Planning
Process.
Call them
decision
aid systems, call themdecision
support systems, or callthem computeraided
planning
systems. Whatever their name,corporateandmilitary
planners arelooking
tothecomputertoalleviate some oftheburden
ofthe planning process.
Using
artificial intelligencetechnology,
or moreprecisely
expert systemtechnology,
systemshave been
developed
atboth
the strategic and thetactical
level.
In
this section we willlook
at the use of expert systemsin the
planning
process.We
willdiscuss
the overallfeasibility
ofusing
application area.
We
will thenlook
at several ofthe systems that are eithercurrently
in
use or understudy.2.3.2.1. Expert Systems
in
the
Planning
Process.
Computer
aidedplanning
systems are not new.They
have been
in
existenceas practical
tools,
and as researchtopics, for
atleast
20
years[Tate
85,
Merry
85].
They
have
progressedfrom
singleactivity
toolsin
the corporateboardroom
to the staff agencies of themilitary
services. As the researchadvanced, expert systems were, and continue to
be,
designed for broader
applications.
Because
an organization's successis
predicated onits
ability
toplan successfully,
it
wassoon realized thatany
tool thatcould reducethetime
spent
in
theplanning
process whileimproving
its efficiency
wouldbe
awelcome addition to
any
executive's arsenal[Palmer
86].
Being
able toproduce an effective plan
quickly
has
become
anecessity
tosurvival.The
marriage of artificialintelligence
techniques and organizationalplanning
seemed naturalfrom
the start. Both areasdeal
with search, choicemaking,
knowledge
representation, andlearning
[Tate
85].
Planners
mustobtain
knowledge
about their own company, the market, competitors, etc.,and
be
able todetermine
which pieces of information are applicable to thecurrent situation.
They
must thendecide
what todo
with thatinformation
and,
based
on previously madedecisions, they
must make new plans.In
addition, expert systems and
planning
both
require solutions tobe justified
thatexpert systems
have become
valuable toolsin
the corporate andmilitary
environments.
[Tate
85]
lists
over adozen
applications tackledby
computer aidedplanning
systems.
Obvious
areas such as robot control(using
STRIPS)
and electricalcircuit
design
(using
NASL)
were on thelist.
Some
not so obvious systemsincluded
ahouse
building
planner(using
NONLIN),
ajourney
planner(using
OPM),
andAIRPLAN,
an aircraftcarrier mission planner.The
range of applicationsfor
expert systemsis
as varied as the users ofplanning. As can
be
seen, areas whereplanning is
used rangefrom
simplemovement to
design
to travel tomilitary
mission planning.In
general,however,
planning
becomes
the method todetermine how
to getfrom
onstateof
being
to another. Whethera robotarm movesfrom
Point
A toPoint
B,
ora currentflows
from
Switch A to DiodeB,
or aship
movesfrom
a porttoan armed engagement,
planning determines
the paths taken to achieve theobjective.
In order
for
expert systems tobe
useful tools in theplanning
process,planning
mustbe
definable
in "computer
terms".First,
planning involves
very large
problem spacesthrough which the planners mustweave theirway
to produce a guide
for
achieving
the objective.This
search space canbe
eithera statesearch space or a series of
partially
elaborated plansthatwillbe
connected or
further defined
during
theplanning
process[Tate
85].
Moving
On
many
occasions, plannersdo
theirjob
withincomplete information
[Reichgelt
85].
Some
phasesmay
containdetailed knowledge
while othersmay
containonly
sketchy
outlines.[Tate
85]
lists
nearly
adozen
techniquesfor
searching.These include
means-end analysis,dependency-directed
search, and opportunistic search.
[Kaiser
78]
takes thisincomplete
knowledge
problem onestep
further
and suggestsheuristic
search.This
method allows
for
solutions tobe
obtained,but does
not require exhaustive searches of the problem state space.In
actuality it is
the method usedby
expertstofind
solutionsin
their areas of expertise.This ability
towork with unquantifieddata
and tobe relatively
unaffectedby
errors orfailure along
paths ofreasoning
makethem quite suitablefor
planning
purposes.As people
formulate
new plans,they
rely
on the results of previous plans aspart of the
input
to the new plan.The
success orfailure
of those previous plans and their impact on theplanning
environmentbecome
part of thedatabase
on which the next planis
built.
The parallel artificialintelligence
construct to this process
is learning.
Theupdating
of constraintfiles
referencedby
theexpert system comesabouteitherby
thedirect
input
oftheuser or through internal modification of the
database
as results of previous actionsbecome known
to thesystem.Another area where the
technology
comes to thefore
is
in
the sheer size ofthe search area. Often the planning process
is very
complexinvolving
numerousinputs
to the planner[Sackman
72].The
overwhelmed executive will tend toignore
many ofthe variables presented tohim
and concentrateplansthatrequire constant
tweeking
astheignored
variablescomeinto
play.A
knowledge-based
system canhold
the entire spectrum ofvariablesand canincorporate
their effectsinto
a plan as required without conscious effortby
the planner.
2.3.2.2. Some Examples.
In thissection we will
look
at some ofthemany decision
support systemsthatare
in
existence today.We
will examine them to seehow
they
define
theplanning
process,how
they
assistthe planner, and some ofthebasics
oftheirdesigns.
This
willlead
us to somedesign decisions for
the expert system ofthis paper.
The
systems we willlook
at areBATTLE,
DECIDEX, TATR,
TACPLAN,
and INTACVAL.The
first
system,BATTLE,
"provides
recommendationsfor
the allocation ofofaset of weapons to a setof
targets"
[Slagle
85]. It
can eithertake a set ofdata
and provide a recommendation orcarry
on a conversation with the userinteractively
and provide recommendationsbased
on user-alteredinput.
BATTLE uses
55 factors relating
weapons,targets,
andbattlefield
situationsin
its
determinations. Thesefactors,
represented as tuplesin
thedatabase,
include
theprobability
thata given weapon(in
this case, artillery) can reach agiven
target,
target size,hits
required to reduce the target toin
effectuality,
whether the weapon
has
sufficient ammunition todo
thejob,
whether theweapon can
be
resupplied andhow
quickly, and whether a single weapon ora
group
of weaponsis
required against a particular target.To carry
on asystem guides the
questioning
ofthe userfor
further information
based
on the ratio of probableimportance
to the situation athand
to thedifficulty
in
obtaining
the answer.Questions
withhigher
ratios get askedfirst.
This
reduces the questions askedby
allowing
gapstobe filled
by
data
related to the question andits
answer.Once
sufficientdata
is
gathered, eitherfrom
the userorfrom
thedatabase,
BATTLE analyzes the effectivenessof each weapon against each target.The
results of these analyses are
fed
to an algorithm thatlooks
at the possible composite allocations ofweaponry
and attempts to optimize the number oftargets thatcan
be
totally
reducedin
value. BATTLE usesapruning
algorithm to reduce the search space to a manageablelevel
rather than search the myriad of possibilities available.The
authors claim this algorithm"executes
in
acceptable timeand yieldsnearly
optimal results."
DECIDEX,
discussed
in
[Levine
87],
is
adecision
support system thatmakes use of several expertsystems to provide adviceduring
theplanning
process.The
creatorssee
planning
as a processofmaking
decisions,
where eachdecision is
reachedbased
on a set ofpreviously
made subdecisions.They
believe
that plannersdo
not makedecisions
in a vacuum,but
rely
on theinformation
passed to them
by
various experts withintheplanning
environment.Even
so,many
of thedecisions
made arebased
upon uncertain andincomplete
information. In spite of
this,
the authorsbelieve
most managers candevelop
some
fairly
good ideasabouthow
theirplanning
will turn out.outcomes of those arrangements.
This obviously
creates avery
complexenvironment
in
whichthe planner mustfunction.
Because
ofthis complexity,uncertainty
andincompleteness,
the authors seethe need
for
several expert advisors to the plannertohelp
fill
in
the gapsin
the planner's reasoning.
This
fill-in
takes theform
offacts
writteninto
thedatabase
or ofheuristics
written as rules.These
allow the respective expertsystem to renderthesubdecisionsthe plannerneedsto continue.
DECIDEX
interactively
helps
the planner tobuild
scenariosusing
adatabase
of
history
about previous plans and their results, a spreadsheet tohelp
withcalculations, and several expert systems.
The
expert systems aredesigned
tocontradict an evaluation made
by
the planner.They
start"from
thenegation ofthedecision
maker'spoint of viewandapplying
their rules,they
try
toprove thatthisnegationis
true[thereby]
contradicting thedecision
maker'sassertion "[Levine
87]
Failure
of an expert system to contradictthe plannerdoes
not guaranteetheplanner
is
correct,but
successby
the expert system should causethe plannersome serious second thoughts.
Additionally,
the planner can use theexplanation
facilities
of the expert systems tofind
the exact point ofdisagreement.
The
tactical air targetrecommender(TATR)
[Klahr
86]
is
a prototypeplanning
aid
for
the United States Air Force. At the time the reference was written,airfields and to projectthe effects of
implementing
that plan"[Callero
86].
When
completed TATRis
expected to notonly
select the airfield,but
alsoselect specifictargetsat each airfield.
This planning
aidis
an airborne version of BATTLE. A targetdatabase
contains pertinent
information
on eachtarget,
whichhas been
gleanedfrom
intelligence
sources andfrom
the user as effects of previous plansbecome
known.
The
database
contains80
or morefacts
about each airfield.These
facts
contain,among
otherthings,
what targets are present at the airfield,their potential to
damage
friendly
forces,
their significance to the enemy,andwhat
friendly
forces
wouldbe
requiredtoneutralizethem.TATR
prioritizestheairfieldsinto
four
categories: excellent,very
good, good,and unrecommended. These
initial
categories arebased
on the target'spotential to
harm
friendly
forces.
It then selectsthe targetsin
thetop
threecategories and
determines
whatfriendly
resourcesit
would cost to achievethe
desired
results against each airfield. These computations are calculatedwith
input
from
databases
that contain notonly factual
data
about thefriendly
forces,
but
also strategic and tactical policies stated as constraintrules. After analyzing each target's
defenses,
alist
of specific targetsis
generated. Then the current resources are matched to
targets,
and a planthat shows
target,
types of aircraft, types of munitions, and otherinformation
is
provided to the user.The
user then makesinteractive
adjustmentsto the proposed
list,
and TATR generates modifiedlists
until theTATR
is
expected tobecome
avery
large database
oftargeting
knowledge
that will serve as a
learning
and research tool.By
planning "what
if"scenarios, the Air
Force is
expected tobe
abletodetermine
optimal minimumforce
allocationsin
different
theaters of operationin
times of reducedresources.
If
notenoughinformation
is
availableto the planners, thelack
ofit
willsignalfuture intelligence
requirements.The
last
system we willlook
atis
actually
two. TACPLAN andits
successor,INTACVAL,
aredesigned
to aidArmy
personnelin
developing
tactical plansfor defensive
purposes.Designed
for
use on microcomputers,both
systemshave
a graphicsinterface
thatuses an
interactive
videodisk.
The
disk
containsmaps oftheterrain overwhich
Army
units are expected to move.Using
maps that are storedin
various
levels
ofscaling, planners can view overall terrainfeatures
or zoomin
on particular sections of
any
map. Because the maps arethe results ofactualaerial reconnaissance,the planners can
literally
fly
over the expected routesofmovement
using joystick
ormouse control.TACPLAN's
databases
areactually
constraintsto whatthe plannerintends
todo.
These databases
contain rules,facts,
andheuristics pertaining
to combat,terrain,
military
doctrine,
weather, and mission types. As the planner placesunits onthe maps and
draws in
intended routesoftravel,
TACPLAN evaluatesthis information and will warn the planner
if
a particular rulehas been
violated.
The
planneris
thenfree
to reroutethe particular unitand cleartheBecause
thedatabases
are"primarily
oriented to therelationship between
terraintype,
maneuverability, and unittype"
[Andriole,
et.al.86],
TACPLANconstrains what the planner wants to
do
rather thanhow
theplanning
process
is
performed.TACPLAN
has
an explanationfacility
that providesnormal English statementswhenever
it
tells the userof a violation.The
creatorsfelt
thatArmy
planners,and planners
in
general,wouldbe
more amenabletoa systemthatacted as a"support
[to]
theway
they
actually do
business"[Andriole,
et.al.86].TACPLAN's
follow-on,
INTACVAL,
goes onestep
further
in
theplanning
aid spectrum.While TACPLAN
assisted the plannerby
advising
of constraintviolations, INTACVAL
actually
guidestheplanning
process and can generateplans of
its
ownfrom
user providedinput.
It
also assesses alternative plansbased
onits knowledge
oftacticalplanning
and allows the userto seehow
different
plans compareagainstone another.Two
majordifferences
between
TACPLAN and INTACVAL are theobject-attribute-value
(OAV)
data
structure and thebattle
calculator.The OAV's
encapsulate information and allow the use of
direct
inferences in
thedetermination
of constraints or constraint violations. Forexample[Andriole,
et.al.
86]:
OBJECT
IF:
terrainTHEN: unit
ATTRIBUTE
forested
armored
VALUE
low-maneuver
Identifying
the set ofOAV's
that pertain to tacticalplanning
allows thesystem to search
for
patterns.These
patterns representthe various conceptsof
operations,
whichin
turn guide the process of plandevelopment
andcheck the planner's
judgement for every
unit and route suggested.The
OAV's,
through constantupdating, also representthelearning
mechanism ofINTACVAL.
INTACVAL's
battle
calculator generates alternate plansbased
onuser-provided operational concepts.
Taking
this general concept, the calculatorevaluates the
terrain,
the currentforce
structure,logistics,
and such andgraphically displays
alternate plans.The
user can watch various plansbe
executed and then call up comparisonsofthe plans
in
orderto evaluatetheirperformance against
known terrain,
doctrine,
and combat constraints.The
planner can thenusethis
information
todevelop
stronger plans.INTACVAL
movesbeyond
theadvisory
role of TACPLAN andinto
the role ofan actual associateofthe planner. It not
only
storesknowledge but
usesthatknowledge
in
theformulation
of plansthatthe user can examine, evaluate,and
modify
asdesired.
Even so,it
mustbe
rememberedthat regardless ofits
role, the
planning
aidonly
generates orhelps
generates plans.The
final
2.3.3.
Planning
in Football.
The
previousdiscussion brings
usto the point ofthis paper.Corporate
andmilitary planning
canbe
paralleledin
thedomain
ofthe game offootball.
The
strategiclevel,
where overall goals and objectives aredetermined,
andthe tactical
level,
where specific actions are planned to achieve those goalsandobjectives, each
have
theircounterpartin
football.
The
elements of eachlevel
also areclosely
relatedto those thatcomprisethe respectivelevel in
thegame.
This
leads
to thedistinct
possibility
that,
if
computer aidedplanning
systemscan
be
ofbenefit
in
thecorporate andmilitary
environment,they
canbe
ofbenefit
in
the sports environment.2.3.3.1. Strategic
Football.
At the strategic
level,
football's
main objectiveis
tosimply
winthegame.The
obvious question
becomes:
How? The coach andhis
staff mustdetermine
this and,
in
the process,formulate
thebest
overall plantoachievethisgoal.This
game plan will guide the coach andhis
playersduring
the tacticalportion ofthe
planning
process. Becausestrategy in football is
"the
scienceorartof
deploying
your own attack against an opponentandattempting
tooutmaneuver him"
[Tallman
69],
the game mustbe
viewedfrom
severalpossible positions ratherthan
from
a singular overall point of view. For thisactually
a sub-plan thatdeals
with particular situations thatnormally
ariseduring
any
game.noruiu
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Rather
thantry
to attack the opponentin
some overall manner, the coachlooks
at these significantaspects,
reviewshis
team and the opponent andselects playsthat
he
expectswillbe
successfulin
thosegeneral situations.The
plays are
usually listed
in
order ofexpected results,with thebest
atthehead
ofthe
list.
Like
the corporate executive and themilitary
commander, the coach muststudy his team,
thebattlefield,
andhis
opponent.He
must weigh theinformation he has
onhand,
balance his
resources against anticipated needs,and reach conclusions as to which course of action would
be
of greatestbenefit.
In
studying his
ownteam,
the coach must evaluateevery
player as to thatplayer's capabilities and abilities. At each practice session and
during
every
game, each player
is
watchedfor
strengths and weaknesses. To gain theadvantage, the weaknesses must
be
atleast
reduced,if
not eradicated.Additionally
thestrengthsmustbe
constantly
built
uptohigher levels.
The
battlefield
is
studiedin
termsof where thegameis
tobe
played.Playing
on one's
home field has
adistinct
effect on the players;however,
beating
anopponent on
his home field
can cause playersto reach newheights
ofeffort.Also
included
here
is
the weather, which canplay
akey
rolein
how
theoffensive unit moves againstthe
defense.
Alsoconsideredis
the type offield
the game
is
played on. Some players are more effective on natural grass,As
indicated
underboth
business
andmilitary
planning,knowing
andunderstanding
the oppositionis
absolutely
essential to goodplanning
practices.
In
football
thisis
alsovery
true.Intelligence
reports,in
theform
ofscouting
reports, are read and studiedby
thecoaching
staff on aweekly
basis.
What
defenses
are usedby
the opponent?Where
arehis
best
playerspositioned? How
does his defense
movein
relation to various offensiveattacks?
All these
factors
are studiedconstantly
by
the coach andhis
assistants. Asnew
information
becomes
available, modifications are made, and,in
theweek
before
the game, the game planis
generated. Team practicesbecome
focused
on the particular opponent andhis
style of play. Adjustments aremade to
deal
with expected ploys, and the teamfinally
enters theplaying
field
todo battle.
2.3.3.2.
Tactical Football.
At thetactical
level,
football
has
asits
objectivethemaking
of 10yards withinfour
attempts.This
allows theteam to retain possession oftheball.
Failure
to make 10 yard will result
in giving
up theball
to the opponent.Without
possession ofthe
football,
thecoach cannot achievethestrategic objective ofwinning the game. Because the tactical
level
ofplanning is
concerned withthe specific actions needed to
be
taken to achieve the strategic goal,play
Using
the game plantostart and,if
initially
successful, to continuethe game,the coach modifies
his
thinking
as the gamedevelops.
As the opponentchanges, so must the coach.
Every
changeby
the opponent mustbe
countered
by
the coach,orthestrategic objective willslip
away.Have
playersbeen
movedfrom previously
scouted positions?Has
thebasic defense
been
changed?
Do
they
rushin
situations wherethey
were scouted tohold back?
And so on.
Using
his frontline troops,
the players, andhis
assistantsalong
the sidelineand up
in
thebooth,
thecoach gathersadditionalintelligence
on the currentsituation.
Coupling
this new information with the game plan andfeedback
from
previousactions, thecoach selectsthe nextcourse of actionfor his
team.Each play
selectiondetermines
the exact actions the offensive unit mustperform to achievethe next portion ofthe tactical plan. This next portion
is
usually
thenext 10yards ofterritory.2.3.3.3.
Using
the Computer.
With
the wealth of informationkept
by
thecoaching
staffin its
scouting
reports, player assessments, and situational references,
it
seemslogical
toaddress the use of a computer to aid the
planning
process. As the seasonprogresses, previous information
is easily
misplaced,lost,
orforgotten.
Being
abletoaccessthis material andto use
it in
theformulation
ofgame plans andOne
ofthe mainbenefits
is
theconcept of corporateknowledge.
The
expertused
in
this paperdoes
notkeep
recordsof previousyears'
efforts or results.
While in itself
thisis
no greatloss,
theidea
thatsomevaluablelessons
may
be
lost
and,therefore,
notbe
available at a crucialtime,
could spell thedifference between
success andfailure.
Also,
information
on opponentsfrom
previous years,especially
when the same coach returns to thejob may
provide
just
thatextrainsight
neededtowinthekey
game oftheseason.Additionally,
the computer, as arepository for
a particular coach'sknowledge,
wouldcertainly
provide ayoung
quarterback with atremendously
effectivelearning
tool.With it
he
could run game simulationsand see
how his
coach wouldhandle
particular situations.This
could proveinvaluable
attimeswhen the coach could not getthe nextplay
selection sentin
to the quarterbackin
time.Programmed with an
opposing
coach's expertise, thedefensive
coordinatorwould
be
able to trainhis
players asto whatto expect. Thiswould enhancethetactical
defensive
play
and could returntheball's
possessionsoonerto the3. Project Description.
This section of the paper describes COACH. First is
described
what COACH does.Secondly,
we'll look at the expert philosophy that was used to build COACH.Next, the structure of the expert system is described. Finally, we
will look at the specifics of COACH'S implementation.
3.1. Design Overview.
COACH is a multi-file planning assistant for a high school
football coach. It is a compiled C code program generated from files created using
RuleMaster,
an expert system shell based on example tables and Turbo C, a commercial C compi ler.3.1.1. What COACH Does
At the strategic level COACH uses a modifiable player
comparison file containing information matching offensive
players'
abilities against their expected defensive
opponent. This file is coupled with another file containing information about the upcoming opponent which is gathered through user input using a question and answer session.
This parallels the head coach's interrogation of his scouts
and his reading of their scouting reports. The strategic
expert system then generates a file containing the game
plan. The game plan can then be displayed on the screen or
printed out as hardcopy. Screen