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Little Lesson 4: Outflanking
Outflanking is a little trick that can be used to drive the enemy king away from its defensive post. The defending king
is forced to give way, allowing the attacking king to reach the square desired. A few examples:
In the first two of these positions, Black is lost no matter whose move it is. In the leftmost position, Black's king has
only one square--d7--from which to
defend the e-pawn, but White's king has two squares--f7 and f6--from which to attack the e-pawn. If it's Black's move, he
has to move away from the defense of the e-pawn; if it's White's move, he plays 1 Kf6--a form of
tempo move--and then Black's king is forced to abandon the e-pawn's defense. For
example, 1 Kf6 Kd8 2 Kxe6 Ke8 (otherwise, 3 Kf7 ensures the White e-pawn's promotion) 3 Kd6 Kd8 4 e6 (White may play 4 Kxc6,
but he needn't bother) 4 ... Ke8 5 e7 Kf7 6 Kd7, and the e-pawn queens.
In the middle position, it might appear that Black's king can keep White's king from penetrating, but the White king
is able to outflank the Black king. For example, if it's Black's move: 1 ... Kf8 2 Kg6 Ke7 3 Kg7 (Black's king now tries
to stop White's king from reaching f6, but has only e7 from which to defend f6; but White's king has both g6 and g7 from
which to attack f6. The Black king will have to give way) 3 ... Ke8 4 Kf6 Kd7 5 Kf7 (notice that the kings have gone from h7
and f7 to g7 and e7 and now to f7 and d7), and we're back in the leftmost position, from which White wins. If, in the
middle position, it were White's move, he would move 1 Kh6, with a continuation like 1 ... Kf8 2 Kg6 Ke7 3 Kg7 Ke8 4 Kf6
Kd7 5 Kf7 or 1 Kh6 Ke7 2 Kg7, etc., or 1 Kh6 Kf8 2 Kg6 Ke8 3 Kf6 Kd7 4 Kf7, again back in the leftmost position. The White
king can get from h6 to g6, because the Black king can't defend g6 from any square other than f7, while the White king can
reach g6 from either h7 or h6. The White king can therefore gain time, if it starts on h7, by moving to h6, or, if it
starts on h6, by moving to h7; the Black king then has to give way. Similarly, the White king then gains access to f6, and
finally captures the e-pawn, because of the Black king's inability to "sit still" and continuously defend f6 or e6.
The rightmost position is the key position. Black to move draws by taking the opposition: 1 ... Kg7 2 Kh5 Kh7
(not 2 ... Kf7?? 3 Kh6, and White outflanks Black as above) 3 Kg5 Kg7, etc. However,
White to move wins by 1 Kh6, and White outflanks Black as above, reaching g6 and then f6 before capturing on e6.
Compare these three positions:
These three positions look an awful lot alike, and yet they differ crucially. In the leftmost
position, the Black king is on the defensive: White's king threatens to penetrate on f6, and
the Black king must try to prevent it. In the middle and rightmost positions, White's king
is on the defensive, trying to prevent Black's king from penetrating on f5 (and, from there, to
e4). The outcomes of the games differ, too: In the leftmost and rightmost cases, the defending
side loses if his king must give up the opposition, and draws
otherwise; the middle position is drawn no matter whose move it is.
The leftmost position is a draw if it is White's move but a win for White if it is Black's move.
The middle position is drawn.
The rightmost position is a win for Black if it is White's move but a draw if it is Black's move.
In the leftmost position, Black's king guards both f6 and h6, and only needs to cover h6 if it's
White's move: 1 Kh5 Kh7 2 Kg5 Kg7, etc. But if it's Black's move, the king has to give up its
protection of either f6 (in which case the White king penetrates to f6) or h6 (in which case the White
king moves to h6 and outflanks the Black king [1 Kf7 Kh6 2 Kf8 Kg6 3 Ke7 Kg7 4 Ke8 Kf6 5 Kd7 Kf7, etc.]).
In the rightmost position, if it's Black's move,
White's king simply maintains the opposition, drawing: 1 ... Kf5 2 Kf3 Kg5 3 Kg3, etc., or 1 ... Kh5
2 Kh3 Kg5 3 Kg3, etc. However, if it's White's move, he must give up coverage of either f5 or h5.
Play might continue 1 Kf3 Kf5 2 Ke3 Kg4 (outflanking) 3 Kd3 Kf3 4 Kc3 Ke3, or 1 Kf3 Kf5 2 Ke3 Kg4
3 Ke2 Kf4 4 Kd3 Kf3 5 Kd2 Ke4 6 Kc3 Ke3, and white's d-pawn falls. (White can put up more of a fight
by 1 Kh3 Kf4 2 Kh4 Ke4 3 Kg5 Kxd4 4 Kf6 Kc4 5 Kxe6 d4 6 Kf6 d3 7 e6 d2 8 e7 d1=Q 9 e8=Q Qf3+
10 Kg5/g6/g7 Kxb4, and Black will win the a-pawn or c-pawn and should win the Queen ending.)
In the middle position, if it's Black's move, 1 ... Kh6 2 Kh4 (White's king is walled out) Kg6 3 Kg4,
etc., draws; if it's White's move, play might continue 1 Kf4 Kh5 (trying to outflank White) 2 Kg3? Kg5,
with the won White-to-move rightmost position; but it might instead continue 1 Kf4 Kh5 2 Kf3 Kh4 3 Kf4,
blocking out the Black king, or 1 Kf4 Kh5 2 Kf3 Kg5 3 Kg3, with the drawn Black-to-move rightmost
position. Thus, White must be careful, on 1 Kf4 Kh5, to avoid slipping into the rightmost position
with himself to move, as in the 2 Kg3? Kg5 variation.
Next, here's a simple example of outflanking together with the opposition:
White to move draws (see the opposition). However, Black to move
wins. Black's king must give up the opposition, allowing White's king to outflank it: 1 ... Kc6 (giving
up the opposition) 2 Ke5 (outflanking) Kd7 3 Kd5 (taking the opposition) Kc7 (giving up the opposition)
4 Ke6 (outflanking) Kc6 5 d4 (mustn't leave the pawn behind!) Kc7 6 d5 Kd8 7 Kd6 (not 7 d6?? Ke8 8 d7 Kd8
9 Kd6 stalemate) Kc8 8 Ke7 Kc7 9 d6+, and the pawn will queen. (A handy fact to know is that in a king-
and-pawn vs. king ending, if you can get your king on the sixth rank in front of its pawn, as after 7 Kd6,
then you'll win, no matter whose move it is.)
Here's a position from an unplayed variation that could have arisen from position 136 from Jeremy Silman's
book How to Reassess Your Chess (see tempo moves), altered by removing
the kingside pawns--and, in the righthand position, by removing the a-pawns as well:
If it is White's move in the lefthand position, should he trade his beautiful knight for Black's bad bishop?
Of course he should: the White monarch will then be able to outflank Black's and win the c-pawn, d-pawn, and
game. 1 Nxb7 Kxb7 2 Kd7, and Black can't continue to protect his c-pawn. If, however, the a-pawns are
removed, as in the righthand position, should White still make the trade?
In fact, he should. The Black king will have both b7 and b6 available from which to defend the c6-pawn, and
yet the White king will still be able to outflank it: 1 Nxb7 Kxb7 2 Kd7 Kb6 3 Kc8! (cutting off b7; since the
Black king is already on b6, and since Black has no tempo move available, the Black king will have to give up
its protection of the c6-pawn) Kh6/h7 4 Kc7, and the White king will dine on Black pawns, winning the game.
The following two positions illustrate the importance of the opposition in determining when outflanking
will work and when it will not:
White to move: White wins
Black to move: Drawn
White to move: Drawn
Black to move: White wins
In the position on the left, White wins by taking the opposition with 1 Kd7.
Black must then give up the opposition while defending c6, so he plays
1 ... Kb6; then 2 Kc8 outflanks as above. But if it's Black's move, he draws
by taking the opposition: 1 ... Kb6 2 Kd7 Kb7, followed by 3 Kd6 Kb6 or
3 Kd8 Kb8 4 Kd7 Kb7, etc. The position on the right is just like it, except
that now White to move gives up the opposition by 1 Kd8, whereupon Black takes
the opposition by 1 ... Kb8, preventing White from making progress. Black's
king creates a c8-c7 wall, blocking
White's king. But when Black moves first, he has to let White's king penetrate,
and he loses by being outflanked: 1 ... Kb6 2 Kc8 (outflanking) Kh6/h7 3 Kc7,
winning for White.