With the last two articles we explored the importance of the long diagonal in queen and bishop (Q+B) endgames. Today we will look at endgames where the attack takes place on the shorter adjacent diagonals, while playing white these would be a2-g8 and b1-h7. Why are these diagonals more important than let's say the a4-e1 diagonal? The reason is that usually important targets are located on the diagonals a2-g8 and b1-h7. If the black king is castled on the short-side then the likehood that the pawns that defend the king are located on these two diagonals is very high. If on the other hand the pawns have moved up, the squares behind the pawns become weak and white can conduct his attack on these weak squares.
The three examples that we will look at today deal with white exploiting different targets along the a2-g8 and b1-h7 diagonals. We will study typical methods of attacking these targets and a few methods for the weak side to defend them.
We observe material equality in the above position. There are pawns on both wings so there is a chance to play for a win (with pawns only on the same side the likehood of a draw is very high). Another important aspect of the position is the presence of opposite-colored bishops. This means that if the queens are traded the game will be a draw but with the queens still present one or the other side can create an attack. It is white to move and we have to find a plan or a target for an attack. The f7-pawn is an ideal target because both queen and bishop can attack it and there is no other pawn that can defend it. There is very little point in attacking the g6-pawn, for example, because the f7-pawn is guarding it. Notice, that the reason that the f7-pawn is vulnerable is that the e-pawn advanced far. White does not have a weakness on f2 because the e3-pawn covers it along the a7-g1 diagonal. The first step of the plan is to tie the black queen down to the defense of the f7-pawn. Usually, we want our queen to be in front of the bishop so in case the f-pawn moves we get checkmating threats.
White has almost accomplished the plan. What are the benefits? At first, it is very hard to see anything specific besides the centralization of the white pieces. However, if you look closer you will notice that the e4-pawn is weak and can only be defended twice with the f-pawn move. But with the Q+B black has to be extremely careful not to open his king to a checkmating attack. It turns out that the best chance for black to defend was to push f5 right away. f5 is a very committal move because it creates the weakness of the g8-square. Nevertheless, it had to be played because with f5 black eliminates the weaknesses on f7 and e4, and by placing the queen on g7 black can cover the weakness on g8. Black did not find the right set-up and ended up losing the game.
The next example is very similar to the one we just looked at aside from the fact that the bishops are of the same color. This gives the defending side more resources as the bishop can also participate in the defense. The position is equal but the presence of the a-pawns allows both sides to try playing for a win. The white bishop is ideally placed on the long diagonal because it defends the king and protects the a-pawn. Next, follows a long phase of maneuvering, where white is targeting the f-pawn and black avoids the bishop exchange trying to play for a win (the black player is much higher rated).
Black's play was far from perfect but the position still remains close to equality. Here, one needs to defend the f7-pawn. It can be done properly in two ways but black chose a move that blunders the a-pawn, and lost the game. It seems that black's intention was to not trade bishops at all costs. This is a poor decision, and the cost was the game.
The next position is significantly different from the two previous. It is more complex due to the asymmetrical pawn structure and opposite-colored bishops. Black's a-pawn is an advantage because it is a passed pawn. On the other side the f7-pawn is missing and the h-pawn moved to h6 which creates holes around the black king. Clearly, the g6-pawn is a target and white will build the Q+B battery along the b1-h7 diagonal to attack it. Then he will push h4-h5 and win the g6-pawn. In the game black attempted to stop h5 by playing the h5-push himself. After the h5-push the g5-square becomes critical because from there the white queen can attack both g6- and h5-pawns. There is a pin along the b1-h7 diagonal, so h5 will be a weakness.
White played very well and the progress is evident but sometimes even the best effort is not enough for a win if the opponent defends well. Black set-up the fortress and defended all the weak square. The key points to keep in mind are that black queen has to be able to defend g6-pawn, not allow the white queen to g5, and keep an eye on the a-pawn. It can always defend the a-pawn from the e5-square. The g6-pawn can be defended from d6 or f6-squares. How about keeping white queen away from the g5-square? It can get there through the d8 or e7-squares. So, with the Qd6-move black would accomplish all three tasks. In the game he allowed the white queen to the g5-square and this led to the loss of the pawns on the kingside and the decisive attack.
Today we continued with the topic started two articles ago on the importance of controlling the long diagonals in Q+B endgames. After going through these articles you should be able to identify the targets that are located on the diagonal and then find a method of exploiting them. The methods range from undermining the pawns to directly attacking them with the Q+B battery. The next few articles will be dedicated to modern day treatment of the initiative in the endgame.