Checking the King into Position

In all the positions so far a knight has been one move away from striking at two pieces.

We now turn to cases where that is not yet so.

Whereas the previous positions typically re-lied on pattern recognition—you see the structural pattern for a fork in place and look for ways to perfect it—the positions here in-volve the other side of tactical play as well:

examining forcing moves to see where they lead. Most often we will begin the train of thought by examining checks and their conse-quences. Checks are the most forcing of all moves because the choice of replies to them is so limited: your opponent has to reply by cap-turing the piece threatening his king, or by moving his king, or by interposing something between his king and your threatening piece.

And often one or two of those options will be unavailable, reducing more the number of replies you need to worry about.

Pushing your opponent’s king around with checks is a good way to generate tactical op-portunities. Eventually the king may end up in position to be forked (or be used to create a pin, or a skewer, or a discovery—as we shall see later). We already know that kings are ideal targets for double attacks, because when your opponent is in check he rarely will be able to use his next move to launch a counter-attack. This point makes it easier to find fork-ing ideas in the first place; for even if there is no fork yet in sight, you always can ask whether your knight is positioned to attack your opponent’s king. If it is, then one of your background goals as you play with your forc-ing moves is to move another of your oppo-nent’s pieces onto a square of the same color as his king’s, and into a position where you can administer a fork. Likewise, anytime you deliver a check that forces the king to move, consider whether the king has been brought

within fresh striking range of a knight or other piece. Let's turn to examples.

Dg064: White to move

Dg064: In the position White has no forks, so start by examining every available check. Ask piece by piece whether you have any way to attack the king and what would happen if you did—what move would be made in response and what the board would look like after-wards. Here White has just one: Ra8. It re-quires Black to move his king to g7. Now imagine the resulting position and ask what could be done with it—by use of a color scan or by looking for your next check. Either way, see that 2. Ne8+ forks and wins the queen.

Dg065: White to move

Dg065: It would be tempting to play the sim-ple QxN for free here—and erroneous. Don’t play any capture, not even of a loose piece, until it’s clear that you can’t do better. Among other things this means examining checks you can give and their consequences. White has a few with his queen; the most interesting is Qe8. Black’s king is forced to a7 (the White knight seals off b7)—and now rethink the board and ask if new tactical strikes might have become possible. With your knight so

prominently posted it is natural to look for forks it might inflict, which train of thought leads to Nb5+. White wins the queen for a knight.

Dg066: Black to move

Dg066: A quick color scan shows that Black has no potential forks to perfect, so start by examining every check. Here there is just one:

Rxh2+. How would White respond? If he moves the king to f1 or g1, examine the re-sulting position: he loses his d2 rook to RxR (a skewer). So presumably he will instead play KxR. Examine the resulting board.

Black’s knight will be on the dark square where it already sits; White’s rook and king will be on d2 and h2, respectively. So Black then forks them with Nxf3+ and gets back the rook (as well as the two pawns captured along the way).

Dg067: White to move

Dg067: A common sort of position. Again White has no potential forks, but as a matter of course we examine every check. Here there is only one: Bxf7+. Black can reply KxB or Kd7. Then what? Redo the color scan: now White’s f3 knight, Black’s g4 bishop, and Black’s king all are on light squares. Ne5+

forks bishop and king. Notice that Black had thought the White knight was pinned to White’s queen, but since Ne5 is a check Black has no time to take advantage of this; he has to move the king, and then loses the bishop.

Another point to note: the bishop is protected by the Black knight at f6. Do you care? No, because after Ne5 the bishop also is attacked a second time by White’s queen; so if Black recaptures with NxN, White plays QxN and still is ahead a pawn. The question is not just whether a piece is protected; it’s always how many times it is protected compared to how many times it is under attack.

Dg068: White to move

Dg068: Black’s king is trapped; it can't escape to g6 if it's pressured from behind. A natural idea for White thus is Qe8, preparing for the kill on h8—but Black’s bishop guards the square, so White has to look elsewhere for ideas. Start by examining every check. There is just one: Rh8. And Black has only one re-ply to this: KxR. Now reexamine how the board will look. White’s knight and Black’s king and queen all will be on dark squares, inviting the fork Ng6+. You could have ar-rived at the same conclusion by noticing that White can attack Black’s queen with Ng6 and asking whether there is any way to draw Black’s king onto the square at the other end of the fork, h8. A common way to move an enemy king onto a square where you want it is to put one of your pieces on the square, attacking the king and requiring it to move onto the square with a capture to defend it-self—a decoy. Here the White rook can do the job.

Dg069: White to move

Dg069: Start by examining the consequences of any checks you can give: our modus oper-andi. There are four: Ne6 (does nothing), and Qf8, Qg8, and Qh8. Qf8 can be dismissed immediately as it results in RxQ with no gain.

Qg8 is unhelpful because it is met with KxQ, drawing the king to a light square; since all White has is his knight, and since the knight and Black’s queen already are on dark squares, it should be obvious that you would like to draw Black’s king onto another dark square as well. Qh8 accomplishes the mis-sion, forcing KxQ (if the king instead moves to g6 or h6, White plays QxQ, as should be obvious if you are visualizing the White queen on h8; it’s yet another skewer). Now the White knight and the Black royals are arranged for a fork via NxR+.

Another way to see this would be to start with the knight and notice from the pattern of its relationship to the Black king and queen that it is just one move from attacking either of them, but that they cannot be attacked at the same time. To achieve a simultaneous attack, one of them would need to be drawn onto a different dark square. This can be done by moving your queen to a square where you want the king to move, and from which your queen gives check (and skewers the Black queen to boot, thus requiring Black to play KxQ and walk into the fork).

Dg070: Start by examining every check you can give. There are three: BxR (leads to RxB); Qg7 (leads to QxQ); and Qh8 (leads to

KxQ). This last sequence is the most interest-ing one. Why?

Dg070: White to move

Because it forces the king to move, which often creates new tactical openings. Here it results in the Black king and queen and White knight all being left on dark squares; there is a fork at f7. But wait: what is Black’s reply to 2. NxR+? He can play Ra7xN, in effect trad-ing a rook for White’s queen and knight! The problem for White, of course, is that the fork-ing square (f7) isn’t safe. We have ways of handling that, however: here, start by taking the piece on the forking square in some other way and see if the piece that replaces it after a recapture might then be loose. Hence White plays 1. BxR, RxB; then comes 2. Qh8+, KxQ; 3. NxR+, forking and then taking Black's queen. White wins a queen and two rooks in return for a queen and a bishop.

Dg071: White to move

Dg071: Standard procedure starts with an inspection of any checks you can give. One of them is Nc4. On a board so open you might be tempted merely to conclude that the king then gets away, but don’t be satisfied so eas-ily; try to figure out where it will go. It’s easy

here because many of its apparent flight squares are unavailable (e.g., d4, d5, or e6).

Indeed, Black has only two possibilities: Ke4 or Kf5. Now look for your next check—or, since you are playing with your knight, look for a fork. If Black plays Ke4, you have Nd2+; if he plays Kf5, you have Ne3+. In either event you win the queen next move.

The important lesson is to observe how im-probable a knight fork might have seemed in the original diagram given the distance of the knight from Black’s queen. It turns out that two jumps of the knight can cover a lot of ground; if the first of its moves requires a forced response from your opponent, you may end up with a fork on the other half of the board from where you began.

Dg072: White to move

Dg072: Start by examining every check, how-ever briefly. There are two. The first, Qxf5, loses the queen, so the follow-up had better be spectacular; and it isn’t. But then there is Rh6.

Consider Black’s possible responses; visual-ize the rook on its new square. If Black moves the king out of the way—say, to g7, or g5 (taking the knight)—White wins the queen by playing RxQ (another example of a skewer).

So assume Black will play KxR. Now how will the board look? White’s knight will be on a dark square, along with Black’s king and queen, which can be forked with Nf7+. So Rh6+ effectively wins the queen.

Dg073: Start by examining every check you can give. There are two: Qh7 and Qh8. As you examine these, you also should notice that White’s knight can strike against the Black queen in one move—Nxe6; if Black’s king could be forced onto a dark square on

which it could be forked at the same time, White would have the game. Does Qh8+ ac-complish this?

Dg073: White to move

No; Black replies BxQ, and anyway if the king were to move to h8 it would be too far away from e6 for White to fork with his knight. What about Qh7+? The difference is that the queen would be guarded by White’s knight, which also attacks f7. Thus Black would have to move his king to f8—and into a fork. White plays Nxe6+ and wins the queen.

We aren’t finished. Black of course must move his king once it is forked, so press far-ther and ask where it will go. Moving it backward along the back rank is out, because White’s queen is there. He has to play Kf7.

Does White then have any more checks? Yes;

among others he has QxB—which is mate.

The moral of this part of the tale is that when you have two pieces in the vicinity of the en-emy king, and especially when one of them is a knight, always be mindful of the relation-ship between the pieces—how one can protect the other in an attack, how the knight can seal off escape squares in different directions by virtue of the odd shape of its moves, and whether the ultimate goal—checkmate—thus might be achieved.

Dg074: At present Black has no forks; only one White piece is on the same color square as his knight. It might be natural for Black to consider Nh3, creating a threat of mate next move with Qf2 or Qg1. But then you think about what checks White would have in reply

and notice Qc8+—a queen fork that would win Black’s knight on h3.

Dg074: Black to move

So Black scratches that idea and starts by ex-amining every check of his own. There are three: Qd1, Qf2, and Qg1. Qd1 loses the queen without accomplishing anything. Qf2 forces White to reply KxQ and almost leads to a knight fork at d3, but the square is pro-tected by White’s bishop. Qg1 also forces the reply KxQ, but it moves the king to a different dark square. Now Black can launch a fork from e2, which is occupied but unprotected;

NxB+ thus wins the queen a move later.

Dg075: White to move

Dg075: Start by examining every check.

There are three: Ne7 (resulting in QxN; forget it), Rb8, and Rxc6. Rb8 leads to KxR, which is of no use to White; here as in the previous example, all White has is his knight, so draw-ing the kdraw-ing to a square of a different color doesn’t help. But what about Rxc6? As usual, one must actually visualize the Rook on c6 to see all the effects of moving it there. In addi-tion to checking the king, the rook then at-tacks Black’s queen; so if Black moves his king, RxQ. Black thus has to play QxR. When

you picture the outcome of the exchange you realize that it leaves Black’s king and queen on light squares, just like White’s knight; or even without that observation you simply look for your next check and observe that Ne7+ forks Black's king and queen, winning the latter.

Dg076: White to move

Dg076: You know the drill: start by examin-ing every check. There are three to find—

Nh6, Ne7, and Qg4. Start with 1. Nh6, which forces Kh8 or more likely Kg7. What check can White then play? If he tries 2. Qg4+, then Black plays KxN. So 1. Nh6+ doesn’t look very fruitful, at least on inspection of where it leads anytime soon. And Ne7+ just loses the knight. But then there is 1. Qg4+. If Black responds by moving his king, White can play 2. Qg7 and mate. Since moving the king therefore is out of the question and Black has no way to capture the threatening queen, his only remaining option is to interpose some-thing in front of his king. He has to play Qg6.

Pause to visualize the resulting position and ask whether you can do anything with it. Yes, the Black king and queen are now arranged to be forked by the White knight via Ne7+.

Another train of thought leading to the same outcome might start by observing that White’s knight on f5 attacks the g7 square in front of Black’s king, which is exposed; this suggests the possibility of mate if White can get his queen onto g7. The natural route to that result starts with Qg4, putting the queen on the right file. Black’s response is forced:

Qg6. Then you see the fork.

Dg077: White to move

Dg077: Start by examining every check White can give. There are four: Ng6, Nf7, Qxh7, and Rf8 (don't forget to consider every attacker). The knight checks are important because they show you that Black’s king can be attacked with the knight in just one move;

they suggest that White might have a crushing fork if Black’s queen could be forced onto a dark square. Qxh7+ just loses the queen and doesn’t help the forking prospects. Rf8+, however, permits only one reply: QxR. Visu-alize the resulting position and see that it calls for a knight fork at g6. Ask whether the square is protected and see that the h7 pawn appears to be on the job—but it’s pinned.

White wins a queen for a rook and a knight.

Dg078: White to move

Dg078: Start by examining every check.

There are two: Qe6 and (less obviously but critically—examine every piece!) Bd5. Qe6+

loses the queen to NxQ. Bd5+ is more inter-esting. The bishop can’t be taken by any of Black’s pieces, and Black can’t move his king to h7 because of White’s knight. So Black has to play Kh8 (actually he does have one other option we will consider in a moment, but let it pass for now). Now ask how the resulting

board would look, and see that it would invite a fork of king and queen via Nf7+. Again, you might have been helped along in seeing this by observing from the start that White can attack the Black queen with one move of his knight and wondering whether Black’s king might be forced by a check onto the dark square at h8 where it could be forked.

As noted, Black has one alternative to moving his king to h8 in response to Bd5+: he could interpose his f8 knight by playing it to e6. But if you ask what checks White then would have, you see that in addition to BxN+ he now has the better move QxN+, capturing the knight that had previously prevented him from checking with his queen. This would again force Black’s king back to h8 and allow White's knight fork on f7. (With his own knight out of the way, Black also would have the option of playing Kf8, but this leads to mate on the move for White with Qf7).

The reason White should reply to 1. Bd5+, Ne6 with QxN rather than BxN is that if he captures with the bishop, Black’s move of his king to f8 works after all; there is no mating threat because White’s queen still is back on e2, stuck behind the bishop now at e6. The general point is that after administering a check and seeing a response that leaves you short of your goals, examine all remaining checks rather than rushing to re-administer check with the same piece you used the first time. Bringing your queen into your attack can be a particularly potent move, as this

The reason White should reply to 1. Bd5+, Ne6 with QxN rather than BxN is that if he captures with the bishop, Black’s move of his king to f8 works after all; there is no mating threat because White’s queen still is back on e2, stuck behind the bishop now at e6. The general point is that after administering a check and seeing a response that leaves you short of your goals, examine all remaining checks rather than rushing to re-administer check with the same piece you used the first time. Bringing your queen into your attack can be a particularly potent move, as this