Player evaluation plays a fundamental role in the decision-making processes of professional sporting organisations. In the Australian Football League, both subjective and objective evaluations of player match performance are commonplace. This study aimed to identify the extent to which performance indicators can explain subjective ratings of player performance. A secondary aim was to compare subjective and objective ratings of player performance. Inside Football Player Ratings (IFPR) and Australian Football League Player Ratings were collected as subjective and objective evaluations of player performance, respectively, for each player during all 1026 matches throughout the 2013–2017 Australian Football League seasons. Nine common player performance indicators, player role classification, player age and match outcomes were also collected. Standardised linear mixed model and recursive partitioning and regression tree models were undertaken across the whole dataset, as well as separately for each of the seven player roles. The mixed model analysis produced a model associating the performance indicators with IFPR at a root mean square error of 0.98. Random effects accounting for differences between seasons and players ranged by 0.09 and 1.73 IFPR each across the five seasons and 1052 players, respectively. The recur- sive partitioning and regression tree model explained IFPR exactly in 35.8% of instances, and to within 1.0 IFPR point in 81.0% of instances. When analysed separately by player role, exact explanation varied from 25.2% to 41.7%, and within 1.0 IFPR point from 70.3% to 88.6%. Overall, kicks and handballs were most associated with the IFPR. This study high- lights that a select few features account for a majority of the variance when explaining sub- jective ratings of player performance, and that these vary by player role. Australian Football League organisations should utilise both subjective and objective assessments of perfor- mance to gain a better understanding of the differences associated with subjective perfor- mance assessment.
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Several studies in the literature and ample coverage in the media have been devoted to fantasy sports. Intriguingly, the literature pertains to three distinct subtopics involving fantasy sporting games. The first is the evolution of fantasy sports, discussing where it began and their thoughts of where it should go in the future. The second is the legality of it. In the many years of fantasy sports, never was there a thought of its similar structure to illegal sports gambling. That changed in the early 2000s, and still has an impact on fantasy application providers to this day. The third is the analysis and prediction of player performance, which is directly tied to fantasy scoring, i.e., winning/losing.
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This study aimed to develop a model to objectively benchmark professional Australian Rules football (AF) player performance based on age, experience, positional role and both draft type and round in the Australian Football League (AFL). The secondary aims were to identify the stage of peak performance and specific breakpoints in AF player performance longitudinally. AFL Player Ratings data were obtained for all players (n = 1052) from the 1034 matches played during the 2013–2017 seasons, along with data pertaining to the abovementioned player characteristics. Two separate linear mixed models revealed that all factors influenced player performance, with age and experience the strongest in each model, respectively. Post hoc Tukey tests indicated that performance was affected by age at each level up until the age of 21 (effect ranging from 0.98 to 3.70 rating points), and by experience at the levels 1–20 and 21–40 matches in comparison to all higher levels of experience (effect ranging from 1.01 to 3.77 rating points). Two segmented models indicated that a point of marginal gains exists within longitudinal performance progression between the age levels 22 and 23, and the experience levels 41–60 and 61–80 matches. Professional sporting organisations may apply the methods provided here to support decisions regarding player recruitment and development.
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Despite these difficulties, the potential usefulness of a single rating system is clear. Teams can improve performance by identifying and adding undervalued players to their rosters, and the popularity of the sport can be enhanced by increasing debate among fans and pundits. In recent years, a wealth of data has become available, making it more attainable to rate all players using one scale. A rating system or competitor index could also be considered as a commercial product, and the information therein can be sold to the media. In this paper, we describe the development of such a system, the EA Sports Player Performance Index (PPI), the official player rating system of the PL (the top tier of soccer in England) and the Championship (the second tier of soccer in England). We describe the structure and construction of the system. We also highlight issues we encountered during the various stages of the consultation process and development, from initial contact to launch, and the challenges of balancing academic research with industry and cor- porate requirements. We then consider the values for players at the time of this writing, and conclude with a discussion that highlights opportunities for further development.
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Redwood-Brown A, Bussell C, Bharaj HS. The impact of different standards of opponents on observed player performance in the English Premier League. J. Hum. Sport Exerc. Vol. 7, No. 2, pp. 341-355, 2012. The purpose of the investigation was to develop an understanding of how the performance of a soccer team is affected when playing against different standards of opponents in the English Premier League. Twenty-nine Premier League matches were analysed during the 2010-2011 season for 18 selected performance indicators. Standards of opposing teams were defined as being top, middle or bottom depending on their final league position. The participating team was categorised in the ‘middle’ category and eighteen players from the squad were selected to take part in the study. Comparisons (mean±SD) were made between the team’s performances on selected performance indicators against teams ranked as top, middle and bottom. A one-way ANOVA analysed the team’s performance behaviour along with: five positional units (centre-back, full-back, centre midfield, wide midfield, centre forward); and individual player performance behaviour. At team level, successful passes (ρ=0.047) were significantly higher against middle (84.2%) compared with top (83.8%) and bottom standard teams (83.3%). Interceptions (ρ=0.016) were also significantly higher against middle (11.2±8.3) when compared with playing against top standard teams (8.4±5.2). The findings suggested the team generally performed better against middle than top or bottom standard opponents. Possession/passing was highlighted as a key factor influencing the performance at team level, although no account for game state was considered. The findings suggest that differences in individual player performance are not always evident at team or unit level which previous research has failed to address. The current study has shown that player, unit and team performance changes as a function of opposition standard but must be considered in the future in relation to game state. Key words: ABILITY, PLAYING POSITION, OPPOSITION STANDARD, COACHING
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asymptomatic upon return to play, residual effects were seen in their batting skills. They evaluated 66 MLB players placed on the DL as a result of concussion injuries. Hitting metrics such as on-base percentage (OBP) and batting average (BA) were used to evaluate players’ pre- and postconcussion perfor- mance, and a significant decline in performance was seen in the postconcussion period. The purpose of our study was to ascertain the incidence and impact of concussions on MLB players following the implementation of the 7-day disabled list (DL) rule. The rule change, prompted by conspicuous underreporting of concussion symptoms for the fear of los- ing their spot on the roster, encourages players to disclose concussion symptoms openly and earlier. We hypothesized that incidence of concussion would be artificially inflated following implementation of the new 7-day DL rule than before, not because the actual number of concussions had increased, but because more would be reported. In addition, based on previous studies suggesting that risk of concus- sion and magnitude of injury varies by position, we further Table 1 Differences between the standard MLB helmet and the
The hope is that adaptive game technology can be used to moderate the challenge levels for each person, help players avoid getting stuck, adapt gameplay more to one’s prefer- ences, or even detect players abusing the game design to their advantage . In multiplayer games, where the difference in skill and experience between players can be large, adap- tive algorithms are used more frequently than they appear in single player games, where the main challenge is to beat the game AI. Difficulty adjustment , matchmaking, asym- metric roles, and skill and aim assistance  are amongst most common techniques, which are believed to improve PX. When a player feels that the game is responsive to them as an individual, they may feel more immersed in the game world, and they experience a heightened sense of enjoyment when the game matches their abilities .
Villarejo et al. (2015) used performance indicators to measure the characteristics of player performance by position in winning and losing teams. The data were gathered from all 48 matches of the Rugby World Cup in 2011. They found that the scrum-half on a winning team was responsible for significantly more kicks, metres gained per kick and try assists. This study grouped the out-half with the centre positions, as opposed to the study by Lim et al. (2009) who considered the positions individually, restricting the ability to compare data between them. The large number of games analysed by Villarejo et al. (2015), whilst providing greater data stability, may also obscure important data due to a number of mismatches during that tournament. The average points gap in matches between tier one and tier two nations was 20 points, and seven games had a winning margin of greater than 50 points (World Rugby, Formerly International Rugby Board, 2011), therefore the importance of specific performance indicators to match outcome may change, relative to the strength of the opponents. This finding was also identified by Carroll (2013) with reference to Gaelic football. Whilst all players are required to perform a range of skills, some positions require a greater proficiency in specific areas. World Rugby (2015) defined the tactical requirements of the scrum-half and out-half positions. The scrum-half is required to:
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The two primary research objectives of this study were to look at (a) how different dimensions of job performance (i.e., task and team player) may influence overall performance and (b) how three human attributes (i.e., GMA, personality, and biodata) may explain variance in job performance. To achieve these objectives the current study used 256 U.S. Army soldiers attending the Special Forces Assessment and Selection (SFAS) course. There were four research findings in the present study that are particularly noteworthy. Two of the reported findings support the first objective while the final two results support the second objective. First, team player performance was highly significant at predicting overall job performance where task performance was only marginally significant to nonsignificant. Second, the peer assessment method (i.e., rating and ranking) used to measure overall job performance significantly influenced the relationship the two dimensions of job performance had with overall job performance. Third, there was a moderate relationship between personality and biodata and a
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Equity theory and expectancy theory have emerged as the two lenses by which player performance around their period for free agency has been studied. J.S. Adams’ equity theory assumes people are motivated by conditions of equity. Adams suggested a person senses inequity when he/she believes that the ratio of his/her perceived outcomes to perceived inputs is different than the same ratio of another; he proposed that individuals reduce or eliminate inequity by altering inputs, such as their performance. Altering (decreasing) performance was first theorized in the context of MLB free agency at its onset in 1976 by Lord and Hohenfeld, suggesting players who had not reached the opportunity to negotiate as free agents felt under-compensated compared to their teammates who had. Lord and Hohenfeld found empirical evidence that players restored performance once they signed a free-agent contract and began receiving equitable compensation, consistent with equity theory. This study also draws on equity theory, predicting that players who underperformed in their contract year as compared to estimated performance significantly increased performance in their free-agent year to the point it produced added monetary benefit to the organization.
Under the light of these discussions, one may wonder about the relation of our notion with persistence. That is why, in the next two games, we display that the entropic selection of Nash equilibrium does not have any containment relations with the notion of persistence. Consider the 2 player game in table 7, a coordination game, where one of the pure actions, in which players are not coordinated, is replaced by a matching pennies: Here, the set of Nash equilibrium equals the set of persistent equilibria, and is given by s 1
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Till, K and Cobley, S and O’Hara, J and Brightmore, A and Cooke, CB and Chapman, C (2011) Using anthropometric and performance characteristics to predict selection in junior UK Rugby League players. Journal of science and medicine in sport / Sports Medicine Australia, 14 (3). 264 - 269. ISSN 1440-2440 DOI: https://doi.org/10.1016/j.jsams.2011.01.006
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Abstract: Assessment of individual performance of a player in a team game is a complex task. But this measurement is essential to ascertain the impact of several factors on performance of a player in that game, and in turn to formulate strategies of selection of player and coaching them. Analytic Hierarchy Process (AHP), a multi-criteria decision- making approach and a decision support tool, has been introduced by Saaty in 1977. A multi-level hierarchical structure of objectives, criteria, sub-criteria, and alternatives are used here and the weights of importance of the decision criteria are obtained by pair-wise comparisons. Attacking and defending, the two main criteria have the weights 0.70 and 0.30 respectively. There are ten sub-criteria of attacking and seven sub-criteria in defending. The weights of importance of the decision criteria are obtained by pair-wise comparisons. A complex decision making task such as assessment of individual performance in a team game can be successfully done by using AHP.
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often occurs in the football industry since star players develop their own brand based on their popularity and likeability (Guschwan, 2016). It is an activity which allows them to make more money but, at the same time, also gives them the opportunity to promote themselves. Nowadays, top football players are not only part of the football event machinery but also play major roles in the advertising media and show business industry. Consequently, the power of footballers’ personal brand strongly impacts their football clubs, leagues and countries of origin because of the huge fanbase they have gathered (Kucharska, 2018). Probably the best player exemplifying this nowadays is Cristiano Ronaldo, also known from his famous brand name CR7. Krooshof (2017) developed a measure to specifically calculate the PBV of football players. This measure consists of two components: the offline and online PBV. The offline PBV includes five dimensions – excitement, sophistication, ruggedness, competence, sincerity – to which different items were assigned. Based on experts rating these items, the measure creates an average score for offline PBV. This is combined with football players’ online Twitter statistics, representing the online PBV of football players, eventually leading to an end score for the PBV of a football player.
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In the latter case, the entire board is in a classical state, with each of the nine squares being colored in White or Black, but without any row, column or diagonal sharing the same color. This situation is a draw and has a direct correspondent in classical Tic-Tac-Toe. But in Q3T there is another situation that may lead to a draw. Imagine that after a measurement, several squares acquire a White or Black color, forming both a White and a Black “suite” (row, column or diagonal) at the same time. This sce- nario, only possible due to entanglement is also consid- ered a draw. In all other cases, either there are still valid moves available, or a single player can claim victory following a measurement that completes a full row, col- umn or diagonal with the player’s color.
In addition to the non-parametric tests reported in the main text, we tested the effects of the various treatments and player B’s Social Value Orientation (SVO) on the number of reported doubles by applying a generalized linear mixed effect model (with a logit link function), using the lme4 package (37) in the R environment(38). The specific dyads (or individuals in the Individuals treatment) were modeled as random effects to control for their interrelated error terms (39). Both the treatment and player B’s SVO are modelled as dummy variables. Of the 176 B players (140 in the seven dyadic treatment and 36 in the Individuals treatment), one was classified by the SVO measure as competitive, 72 as individualistic, and 103 as pro- social, and none as altruistic. We therefore added the competitive player to the individualistic players, and considered two levels of SVO: 73 pro-self and 103 pro-social players. The regression coefficients and their significance levels, standard errors, and confidence limits are presented in Table S2.
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strategic variables of players are p ’s. We call two players Players A and B, and will show that the maximin strategy and the minimax strategy in the x -game, and the maximin strategy and the minimax strategy in the p -game are all equivalent for each player. However, the maximin strategy for Player A and that for Player B are not necessarily equivalent, and they are not necessarily equivalent to their Nash equilibrium strategies in the x -game nor the p -game. But, in a special case, where the objective function of Player B is the opposite of the objective function of Player A, the maximin strategy for Player A and that for Player B are equivalent, and they constitute the Nash equilibrium both in the x -game and the p -game.
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argued that there is little basis for the assumption that basic voting outcomes should be thought of as different orderings of players along a continuum. This assumption is the basis of the uniqueness property of the Shapley-Shubik index because it ensures that in any vote taken there is precisely one player whose contribution is pivotal. However it means that coalitions with different numbers of members are assigned different probabilities. A coalition with t members (in a game with n players) which player i can join to make it winning has a weight, in the definition of the index, of t!(n-t-1)!/n!. This expression is at its largest when t is very small or very large and at its smallest when t is in the middle of its range. This means that a coalition with a very few or a very large number of members dominates in the calculation of the index. It is not intuitively clear why this should be when the basic idea is to measure the ability of a player to change losing to winning and the size of coalition might seem to be irrelevant.
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The JMF API provides an abstraction that hides these implementation details from the developer. For example, a particular JMF Player implementation might choose to leverage an operating system's capabilities by using native methods. Indeed Sun’s implementation of JMF has different versions each one tailored for one platform.
information leakage to the eavesdroppers. In order to deal with this issue, it is necessary to consider robust transmit jamming to achieve guaranteed outage performance of the secrecy rate. Most of the game theoretic approaches proposed for physical layer security have been assumed that the players have the perfect CSI of the eavesdroppers. In order to overcome the imperfect CSI issues associated with eavesdroppers in the existing games, robust techniques should be considered for secure communications. Therefore, the development of robust jamming games by incorporating channel uncertainties or the cases of no eavesdroppers’ CSI along with the corresponding analysis of equilibria would be very challenging. These robust jamming games could be formulated into Bayesian games, which are well known for the scenarios with incomplete in- formation. The jamming games with imperfect eavesdroppers CSI would be one of the possible interesting future directions in game theoretic based jamming for physical layer security.