Chess Endgames 3: Stalemate Tricks
Last Edited January 3, 2016
Created April 9, 2016
Chess players, even those that are very advanced computers, constantly make mistakes. The most obvious consequence of such a mistake usually results in the opponent gaining some sort of advantage and thus being able to checkmate your king. However, even when the chips are down, there can be some strong ways to make a comeback: sometimes these result in surprise victories, but more often than not, it often ends with the weak side salvaging the game and creating a draw, the next best thing to a victory. One of these tactics includes stalemate: if one side, given his/her turn, cannot move, then the game is automatically drawn. Stalemate is not one of those things that just happens by accident, but is also a clever tactic that the losing side can engineer to make the opponent ragequit without actually losing.
Take Figure 1 for example. Black is up a Queen to White's bishop: this kind of endgame is normally very easy for Black to win, as Black's king and queen can simply move on dark squares to corner the White king. If it was White to move, he could play Bxf5+, drawing the game because Black has no pieces to checkmate with, and White cannot checkmate the Black king with just a King and Bishop. However, it is Black to move here, and White has just played Bc2! Normally, arbitrarily sacrificing material, particularly your last hope in defending against an opponent, seems suicidal, but look carefully in this case. If Black plays Qxc2, White is stalemated, as each square his/her King can go to is covered by the Queen, but (s)he is not in check, resulting in a draw. The natural thing to do then would be to move the Queen away, but look again: White has pinned the Queen to the King, and as a result, the Black queen cannot move to a square where it is not under attack by the Bishop! Since Black must either stalemate White's king or lose his Queen to the Bishop, the game is drawn.
Let's look at another example:
Once again, Black is ahead in material: a Queen and a Pawn, collectively worth 10 points, is valued greater than a rook, which is worth 5 points. But again, White can turn the tables and draw as follows:
|½ - ½|
Once again, notice how Black's queen, trapping White's king in the corner, is once again an advantage for White rather than a liability. White cannot capture the rook with the king, because that would result in stalemate, since the only piece that White has, the king, cannot legally move to any square! Also notice how Black cannot flee along the a-file as it is being blocked by its own pawn, so Black's king has no choice but to shuffle back and forth between those two squares (although Black him/herself does have a choice to agree to a draw).
Stalemate can also occur without the queen trapping the white king in the corner. Let's look at another example:
Unlike before, in this example material is even, but Black's king is in a slightly more advantageous spot: it is closer to the pair of pawns on the h-file, and can readily stop White from defending the pawn on h2. If White plays improperly, the game results in a draw:
The race begins to get to the h-pawns, but because Black is shielding away White's king, Black is certainly guaranteed to snag the h2 pawn.
Black has now grabbed the h-pawn while guarding his own. Now Black must tread carefully: 7. ... Kh1? leads to 8. Kf2! The Black king is now trapped between h1 and h2 and has no way to progress, while White keeps him shut in. Correct is, instead:
|0 - 1|
Black has successfully escorted his pawn to queendom and thus ensured his victory. However, this situation could actually have been avoided, believe it or not. The error here was 1. Kc8?, moving the White king in sync with Black's king and thus making it easier to shield off. The key to winning, in this case then, is an idea mentioned earlier: if White shuffles his king back and forth between f1 and f2, while Black's king is stuck on the sidelines, there is no way for Black to win and the game must draw.
So, White, thinking smartly, literally tries a different route:
Since White cannot capture the black h-pawn or defend his/her own anyways, White instead relies on Black's need to capture the h2 pawn to trap the Black king in the h1 corner, so (s)he chooses a route that gets him to f2.
It is clear now that Black must let White onto f2 or f1 if he wants to capture the white h-pawn; in addition, Black cannot move out of the way either.
Now all White has to do is shuffle back and forth between f1 and f2, while Black can only do the same on h1 and h2. And, if (s)he tries to move the h-pawn:
|½ - ½|
...the game ends in a draw due to stalemate.
The preceding examples go to show that even in situations where one is at a severe disadvantage, smart play can manage to achieve a draw for the losing side. Forcing stalemate, the condition where the moving side is unable to make any legal moves while not having his/her king under attack, is one such way to turn cut one's losses.
Thanks for reading, and stay tuned for more!