1 766
8 7 6 5 4 3 2 8 7 6 5 4 3 2
Yuri Averbakh (473)
a b c d e f g hYuri Averbakh (477)
a b c d e f g h These four positions are worth remembering. Especially Averbakh (473) where Black draws as follows. To improve his position, White will have to play b2-b4 at some point. Black exchanges on b4, and because he keeps a pawn on b6 securing the important c5-square, White's king cannot approach the black king in the corner. Here the coordination between the light-squared bishop, king and pawn on b6 is sufficient for a fortress.Let's imagine that White could play b2-b4 before Black had a chance to play ... a5:
8 7 6 5 4 3 2 a b c d e f g h Lb4 i.f3
Black can try l ... ic2!? to stop White from playing a2-a4. After 2.�g2? ia4 3.�g5 a6 Black prevents White from advancing his pawns, and the pawn on b6 and bishop on the a4-e8 diagonal keep the white king off the queenside pawns. This position is a fortress.
Please note that the position with the a-pawn on a3 is well-known to endgame theory since the game Olafsson - Larsen, Las Palmas 1 974. Dvoretsky, amongst others, has mentioned the position in Dvoretsky's Endgame Manual.
With the pawn on a2 White can chase the black bishop with Wb2-a3, but with precise defence it is nevertheless a draw. It is important for Black to be able to deliver a check on the g8-a2 diagonal once the white king goes to b3 in order to support the pawn advance a2-a4. Instead White should reply to 1 ... ic2!? with 2.b5. This move also provides an alternative win to the main continuation: White wants to play a4-a5, and since Black is forced to take (otherwise a5-a6) he will get access to the important c5-square. 2 ... .idl 3.�f7 .ic2 4.�f4 .ig6 5.a4 Wb7 6.�f6 ie4 7.a5! bxa5 8.Wc5 a4 9.�f7t Wb8 1 0.�f4 .ig2 (Black should cover the c6-square since 1 O ... ic2 1 1 . Wc6+- loses right away.) l l .�xa4 This is not a fortress: a7 is a point to attack and White will play b5-b6 at the right moment; the black king is in the wrong corner.
2.a4 .ie4 3.a5!
fu we just saw, this is not the only path to victory. Also possible was 3.b5 followed by a4-a5.
3 ... bxa5
3 ... �d3 4.axb6 axb6 5.'it>c6 gives White's king access to the queenside. 5 ... b5 6.'it>b6 Wc8 7.1%c7t ©d8 (7 ... ©b8 8.1%d7 �f5 9.1%d8t �c8 1 0.1%e8 Zugzwang. 10 ... 'it>a8 l l .1%xc8 mate! This should be a familiar theme by now.) 8.1%c5 White takes on b5 and wins the pawn ending.
If instead 3 ... �f3 4.a6! White mates on the back rank.
4.bxa5 a6 4 ... �d3
This is a tougher defence, trying to keep the dark square b6 under control.
5.'it>c6 �e4t 6.Wc5 �d3
A waiting move on the diagonal, claiming that a5-a6 would place the pawn in danger, is refuted by: 6 ... �f3 7.a6! �e2
a b c d e f g h
8.1%b7t! White sacrifices the pawn and plays for mate, since the black king is in the wrong corner. 8 ... ©a8 (8 ... 'it>c8 9.1%xa7+-) 9.'it>c6! �xa6 1 0.1%b4 Threatening mate beginning with ©c6-c7. 1 O ... �fl l l .1%f4 �g2t 1 2. '1t>c7 a6 1 3. ©b6!+-
a b c d e f g h 7.1%g3!
·Wherever Black moves his bishop, he cannot prevent both the threats of a5-a6 and 'it>c6. 7 ... �e2 8.'it>c6 a6
Forced to avoid mate. 9.'1t>b6 '1t>c8 1 0.1%g7 +-
We have the study by Enevoldsen in essence. Back to the main continuation after 4 ... a6:
a b c d e f g h s.©cs .td.3 6.©b6 ©cs
Again we have the study by Enevoldsen. White wins.
Let's return to the four fortress positions once again. You might wonder why the position with a bishop's and a rook's pawn on the sixth rank is a draw, as in the first two diagrams, and the position with a knight's pawn is not. The answer can be found in the exercise section,
but at this point I can reveal that it is important for the defending king to be close to the right corner (opposite to the colour of the bishop). Another important position that is not a fortress - albeit it looks as one at first glance - is the following: Kholmov 8 7 6 5 4 3 2 1 973 a b c d e f g h White to play
In contrast to the diagram above with only two pawns each on the kingside, the presence of f-pawns makes the difference between a draw and a win. But in order to win, Black has to sacrifice two pawns.
l . .ic6 gd2 2. ©gl gd6
Black prepares the breakthrough. This is an ideal square for the rook: from here it keeps an eye on the kingside pawns and forces the bishop close to the corner.
3 . .ib7 g5! 4.fxg5!
The best defence according to Averbakh. The alternative was:
4.hxg5 h4 5.gxh4
s.©g2 hxg3 6.©xg3 !!d4 7.©h4 ©xf 4! 8.g6 (8.©h5 !!d3! 9.©h6 !!h3t i o.©g6 !!g3-+) 8 ... !!d8-+ and because of the mating threat, White has no time to support his passed pawn. 5 ... 'it>xf4
Black has sacrificed a pawn (temporarily) but more important is that he gained a passed pawn himself, and that he obtained access to the f4-square, which in essence is the c5-square with colours reversed.
6.�c8 6.'it>g2 !!d2t 7.'it>h3 !!d3t s.©g2 !!g3t 9.'it>h2 Wg4 1 0.�c8 !!h3t l l .'it>g2 !!xh4 1 2.g6 !!h6-+ 6 ... 'it>g3 7.'it>fl f4 8.h5 f3-+ a b c d e f g h 4 ... f4 5.gxf4 ©x:f4
Again Black has gained access to the important f4-square.
6.©£2 ©g4 7.ie4 ©xh4 8.g6 gd7 9.©a ©g5 10.©g3
White is unable to improve the position further, and can only wait for Black to break through.
10 ... ge7 1 1 .ibl h4t 12.©h3 ge3t 13.©h2 gg3 14.ic2 ©f4 1 5 . .ib l gb3!
This is the clearest way for Black to victory. The bishop is trapped and White will have to sacrifice his g-pawn to save it.
l 5 ... h3!?
This is more complicated, but also wins. Averbakh's mainline goes:
1 6.if5
Typical are the following lines: 1 6.g7 E:xg7 l 7.Wxh3 :B:g3t! An important trick ensuring chat the king will not run away from the corner. 1 8.Wh2 ( 1 8.©h4 :B:gl-+ threatens both the bishop and mate on h 1 .) 1 8 ... '\t>f3-+ and the white king is trapped in the wrong corner. Black wins as in the first diagram of the chapter.
1 6 ... Wf3 l 7.ic8!
17 .ixh3 :B:xg6 followed by ... :B:g3 again traps the king in the corner.
17 ... :B:xg6 1 8 .ib7t ©g4 1 9.ic8t Wh4 20.ixh3 E:c6!
In chis line the white king is actually allowed to escape to fl , but the unfortunate separated position of king and bishop secures victory for Black after all.
2 1 .id7
2 1 .if5 E:f6 22.id7 E:f2t 23.Wgl ©g3�+ 2 1 ...E:c2t 22.©g1 ©g3 23.'it>fl
a b c d e f g h 23 ... ©f3!
There are no bishop checks. 24.©e l ©e3! 25.'it>fl
25.Wdl E:d2t drops the bishop. 25 ... E:f2t 26.©e l
26.Wgl Wf3-+ traps the king in the corner. 26 ... E:f7
Black will harass the bishop until he can deliver the deadly check on the first rank.
27.ie8 E:e7!
You cannot hide behind the king! 28.ic6 E:c7 29.ia4 :B:c l t 30.id l E:b l
Zugzwang, and mate in 7 according to my engine.
Back to the game after the better l 5 ... E:b3!:
a b c d e f g h 16.g? gg3 17.ic2 gxg7 1 8.i>h3
Otherwise Black plays ... :B:g3 and brings the king to f2.
18 ... gg3t! 19.i>xh4 gg2-+
Black wins the bishop due to the mating threat on h2.
Already chis study gives an idea of how these positions can suddenly become very sharp, and chat finding the win often means chat you should dare to enter complications.
A very important lesson from chis study is chat when relying on the position as being a fortress, you should be absolutely sure chat it is in fact a fortress. This is why the above handful of fortress positions are important to know by heart, so as to have something to compare with.
At chis point I would like to introduce a useful term:
4.1.2 Fortress-like position
I shall abbreviate fortress-like position as FLP for short. The definition of an FLP is:
Fortress-like position (FLP): A
position of rook vs. bishop that has come to a standstill, where the bishop side cannot improve his position further and only the rook side can try to win it. The characteristic of such a position is that it is not yet clear if the position is a fortress or not.
Analysis will show if the FLP is a fortress or not. And here the knowledge of fortress positions comes in handy. If the position is not a fortress then the bishop side is lost.
We shall see many FLPs in the pages to come, and some of them actually turn out to be fortresses. This is mainly due to the fact that the bishop side has material compensation in the form of at least one pawn.
The following three positions are taken from Averbakh's famous 6-book endgame work:
8 7 6 5 4 3 2