It's been a while since I've done an endgame article, dating back to the early summer when I did an article on corresponding squares in king and pawn endgames. In this article, I'm going to talk about the case of Opposite Colored Bishops (from here on out, referred to as OCB) and Pawns. Many amateurs often view this kind of endgame as an automatic draw. While the draw ratio is significantly higher than the vast majority of other endgames, the draw is not automatic. Here I am going to show you a game featuring the Petroff where Black uses the principles of what to do in an OCB endgame and proceeds to win. Many people would see the Petroff and see the OCB ending and just write off the game as a dull draw. Hopefully this game will make you rethink before you just assume that a position is drawn because it's an OCB ending.
Tuesday Night Action 38, Round 4
W: Vishnu Vanapalli (2008)
B: Patrick McCartney (2090)
Petroff Defense
After the moves
1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Nxc3 6.dxc3 Be7 7.Bd3 O-O 8.O-O Nd7 9.Be3 Ne5 10.Be2 Be6 11.Nd4 Nc4 12.Nxe6 Nxe3 13.Nxd8 Nxd1 14.Raxd1 Raxd8 15.Rfe1 Rfe8 16.Bf3 c6 17.Kf1 Kf8 18.Rd2 Bg5 19.Rxe8+ Kxe8 20.Rd1 Kd7 21.c4 Kc7 22.Ke2 Re8+ 23.Kf1 Bf6 24.b3 Bc3 25.g3 f5 26.Rd3 Re1+ 27.Kg2 Bf6 28.Rd1, we have the following position:
Let's take a look at some of the features of the position, particularly from Black's perspective.
First off, the pawn structure favors Black. Both sides have three pawns on the kingside and 4 pawns on the queenside. However, none of Black's pawns are doubled or isolated while White's queenside pawns are compromised. That said, Black does have one slight problem. The d-pawn. The black king is the only thing protecting it, and it is very difficult for Black to make progress as long as this pressure is placed on the pawn. What does Black do about that?
On the flip side, we see that Black already has firm control over the dark squares on the queenside. If White ever tries to advance one of his pawns to a dark square, Black can move his Bishop, attacking the pawn immediately, and make him advance it again to a light square. This gives White two major problems. The first is that with his crippled pawn structure and complete lack of control on the dark squares, White will never have any winning chances on that side of the board. The absolute best he can do is force the Black pawns onto dark squares to form a gridlock and make the position unwinnable for both players on that side of the board. Over on the kingside, Black already has a pawn on f5, and still has his h-pawn on h7, and can play the move ...g6 at any time if necessary. Therefore, White currently has no control over the light squares, and the only way to force them forward is to attack the pawn chain at the base, and getting the Bishop to g8 to attack h7 will take a long time because Black controls d5 with his c6-pawn and White's own pawns block him from getting to g8 by other means. Therefore, White has no real shot at all on the kingside. So what does this mean for White?
Therefore, we see now what both sides should be shooting for. Black should be trying to win while White should be trying to draw.
With Black to move, he has a major decision to make. Should he trade off the rooks based on what we've looked at for both sides or should he keep the rooks on figuring they will be necessary to avoid the draw? We have already determined that Black has total control of the dark squares on the queenside. With the location of the kings, White's king is far enough away that Black can at minimum get his king to either a3, which will likely win the a-pawn for Black and he can force through a passed a-pawn, or if White advances the a-pawn to a4 (going to a3 Black will simply force it to a4 with his bishop), then the Black king will get in on c3 and virtually force the White bishop to be immobile and stuck on d1 and Black then can advance the kingside pawns to create a second weakness and overload the White bishop. The only thing holding the Black king back is the rook on d1 by hitting d6, and with two very encouraging ideas based on Black's total control of the dark squares on the queenside and White's lack of ability to control the light squares on the kingside, Black sees the rooks as a distraction, not a help, and so Black's decision is simple.
28...Rxd1!
Black trades the rooks and enters the OCB ending.
29.Bxd1 Kb6 30.Kf3 Kc5 31.Ke2
White should probably have thought about 31.g4, attempting to trade a set of pawns. The fewer pawns there are on the board, the more likely White can hold the draw.
31...Kb4
White now has to choose between two evils. Does he play 32.a4 to avoid the immediate dropping of a pawn? Or does he play 32.Kd3 to keep the Black king out of c3, tying down the bishop to d1 pretty much permanently.
32.Kd3
White decides to jettison the a-pawn in order to be able to keep the bishop active. The problem with this is given that it is the rook pawn, Black can create a passer on the a-file, whether does voluntarily by White as in the game, or via Black advancing the a- and b-pawns to create the passer. This passed pawn will cause Black to not have time to counter by attacking the Black pawns on the kingside.
32...Ka3 33.Bf3
Once again, 33.g4 is probably better. After the game move, White's idea is to attempt to pressure the Black pawn chain on b7 and c6 by advancing the b-pawn once the Black king takes on a2, and therefore opening up an entry point on d5 for the White bishop to get to g8. The problem is, this gives Black an uncontested a-pawn and it creates a major distraction for White.
33...Kxa2 34.b4
34...Bd8
Black uses the fact that White can't stop everything to either create a majority for himself on the kingside or else make White spend time on the kingside and execute on the queenside. White decides that breaking up the pawn chain on the light squares is more important than trying to save the f-pawn.
35.b5 Bc6 36.bxc6 bxc6 37.Bxc6 Bxf2 38.Bd7
38...a5!
White was probably banking on Black playing 38...g6 and then trying to play 39.Be6 intending to go to g8 to make Black put his pawns on dark squares, and use his King to stop the a-pawn. Instead, Black leaves the f5 pawn hanging. As it turns out, White has no time to take the f-pawn.
39.Kd2
After 39.Kc3, Black can play 39...g6 and it would take White too long to attack the pawn chain. Note that 39.Bxf5? doesn't work. After 39...a4, White has no way to stop the a-pawn without giving up his bishop once the pawn gets to a2. If Black wins White's bishop, the rest is easy. After the game move, Black puts his king on the ideal square for it, and then relocates the bishop to pressure the White pawns on the kingside.
39...Kb2 40.Bb5 Bd4 41.Bd7 Be5 42.Kd3 f4 43.gxf4 Bxf4 44.h3
44...Bg3
Black completely immobilizes the h-pawn. Black's idea now, with White's pawn immobilized, is to start advancing the majority on the kingside and overwork the bishop.
45.c5
White desperately tries giving up a pawn to make the king more mobile. Of course, it won't work with correct play by Black.
45...dxc5 46.Kc4 h6
The idea here is to be able to take on c2 without dropping the h-pawn as the result of a fork. If White protects his c-pawn, Black can protect his.
47.Ba4 Ka3 48.Be8
Or 48.Kb5 Be1 winning.
48...Bf2 49.Kb5
49...a4!
An important point that Black had to see in advance in order for the line of play selected to work. The king blocks the bishop from covering a4 and therefore allows Black to advance his passer.
50.Kc4
The other critical factor that must be seen is that 50.Ka5 fails to win the a-pawn because of 50...Be1+!
50...g5 51.Kc3 Bd4+ 52.Kc4 h5
Played on the basis that if White takes the pawn via 53.Bxh5, then 53...Kb2 wins.
53.Kb5 g4 54.hxg4 hxg4 55.Bc6 Kb2 56.Be4
If 56.Kxa4, then 56...Kxc2 and the Black king will run to the kingside so that it can force White to give up his bishop for the g-pawn, and then coming back to win the game with the c-pawn. Instead, the game move creates another problem.
56...a3 0-1
White can't stop both the a-pawn and the g-pawn, and so he resigned.
