|
The so-called “advantage of two Bishops” is a rather well known positional factor. There are many situations where pieces of similar stature perform differently. The Bishop is a long-range piece and its advantage over Knights is mostly seen in open and sometimes semi-open positions. In the endgame, the Bishop pair is particularly superior in positions with pawns on both sides of the board. Placed in the center of a board, a Bishop can simply cover more squares than a Knight can. A Bishop may perform both attacking and defending functions, while being far away from a target. A Knight, due to its limited mobility, simply can’t compare. Let’s take a look at the following game, played by the future World Champion.
Arnason – Kasparov
Dortmund, 1980
BLACK TO PLAY
At first sight, this position looks even. In reality, however, Black has an edge even though he has no material advantage. Why is that? As mentioned above, a pair of Bishops is very strong in open positions with pawns on both sides of the board. Black also has a pawn majority on the kingside, and Bishops are great supporters of pawn advances since they can attack the squares in front of the pawns, making defense difficult. White has no outpost for his Knight and his King is relatively far from the battlefield. Generally, Black must push his kingside pawns forward (gaining space and restricting the enemy army). In order to do that, he will move his King forward, while possibly repositioning his light Bishop to a more useful square, e6 for instance. White, in turn, should seek trades and possibly exchange a pair of Bishops. Kasparov wastes no time.
31…f5 32.g3
White stops …f5-f4, since in that case Black could quickly obtain a passed pawn in the center. He hopes to stall his opponent’s advance on the kingside, while moving his own pawns on the queenside.
32…Kf6
Naturally, in order to advance, …g6-g5 is needed. Therefore the King protects its f5-pawn.
33.h4 Bc8!?
Black follows the plan outlined above. In some positions White could play h4-h5, undermining the f5-pawn, and Ba4-d7, attacking f5 again. The text makes Ba4-d7 impossible, and h4-h5 would cost White a pawn. Also, Black’s Bishop on e6 would further restrict his opponent’s Knight.
34.Bd1 h6?!
White insists on preparing h4-h5 and Kasparov moves his h-pawn forward. It’s not clear however, how this move helps Black. Kasparov in his notes considered this move a waste of time, recommending immediate …Kf6-e5.
35.Be2 a5 36.Bb5!?
Here White’s Bishop has access to both the kingside and queenside. In case of 36…g5, White may play 37.hxg5+ hxg5 38.g4! and, if 39…fxg4, then 40.Bc6 Ke5 41.Be8 Bf5 42.Kg2 and it is not clear how Black makes further progress from here. In case of 39…f4 40.Nf5 Bxf5 41.gxf5 Kxf5 42.Bd7+, White keeps good chances for a draw. Kasparov decides to advance his King.
36…Ke5 37.Nc4+ Kd5 38.Ne3+ Kc5?!
According to Mikhail Shereshevsky, Black gives his opponent a chance to draw with this move. For one, White can easily exchange opponent’s a-pawn at any time with b2-b4+.
39.Be8!
This move forces further pawn exchanges. Black must be very careful now, since it would not be possible to win an ending B+B versus a single Bishop.
39…g5 40.hxg5 hxg5 41.Bg6 f4 42.gxf4 gxf4
43.Ng2
As pointed out by Reshevsky, 43.b4+ axb4 44.axb4+ meets 44…Kd4. Black’s King holds a strong position in the center, but there are very few pieces on board. After 45.Ng2 Bc7 46.Be8, intending b4-b5 and Bd7-c6, it would be very hard for Black to win.
After the text move, it looks like White’s defense prevailed. Really, Black now must defend two pawns and 43…f3 44.Ne3 Bb7 does not look terribly promising, since further progress is very hard to make.
43…Kc4!
This is the key point behind Kasparov’s maneuver. The R-pawns are always hard to stop! Of course, here 44.b4? is powerfully met by 44…a4!
44.Nxf4
Shereshevsky mentions that 44.Bf7+ Kd3 45.Nxf4+ Kc2 46.b3 Kxc3 would allow Black to retain his e-pawn. Since White would have a weakness on b3, Black would keep some winning chances.
44…Kb3 45.Bxe4 Kxb2 46.Bc6
It’s possible White thought he could somehow keep the extra pawn, but 46.c4 a4 47.c5 Ba6 looks rather dangerous, due to a possible blocking of the a2-g8 diagonal by Black’s light Bishop. With the text, White hopes to win some time and bring his King over, but it does not work.
46…Kxc3 47.Kf1 Kd2!
This is the best chance. White’s King is kept away from the center and Black hopes to activate his Bishops.
48.Bb5?!
This is a first misstep. Kasparov recommends 48.Nd5! here, preparing advance of the f-pawn. He thinks White has a good chance for a draw after 48…Ba6+ 49.Kg2 Bc4 50.f4! threatening f4-f5-f6.
48…Bf5!
Now in case of a Knight move Black plays …Bf5-d3+, exchanging Bishops and taking advantage of the Knight’s inability to fight the R-pawn. White, however, walks right into it, perhaps as a result of miscalculation.
49.Nd5? Bd3+ 50.Bxd3 Kxd3 51.Ke1 a4 52.Kd1 a3 53.Kc1
This is what White had in mind, but he missed a simple maneuver.
53…Kc4! 54.Ne3+ Kb3
Now the Knight is kept at bay, while Black’s a-pawn is unstoppable. White sets up one last trap.
55.f4 Bc7 56.Kb1!? a2+ 57.Ka1 Ba5!
Kasparov avoids a naïve 57…Bxf4?? 58.Nc4!! and suddenly game is drawn, since there is no defense against Nc4-d2-b1-d2, etc.
58.Nd5 Bd2, 0-1.
The pair of Bishops is even more effective when Rooks are present. A famous German player, Zigbert Tarrasch, even said that a Rook supported by a pair of Bishops is better than two Rooks and a Knight. While it’s unclear whether he was serious at that point, the strength of R+B+B is undeniable.
Ivkov – Hort
Varna, 1962
WHITE TO PLAY
While material is even, this can’t be said about the position itself. White has his Rook on the seventh rank and Black’s queenside pawns are very weak. White’s winning plan should look like this:
* Neutralize the opponent’s Bishop, keeping it from re-entering the game.
* Attack weak pawns on the queenside with Rd7-b7 and a2-a4.
30.g5!!
Grandmaster Borislav Ivkov makes a very powerful move. Black wanted to play …f7-f6 and …Bg6-e8, getting his Bishop back into the game. Now 30…f6 31.gxf6 gxf6 32.Bh6! would give White a winning advantage. Also, 30…Rd8 31.Rc7 Nb8 32.Kg3 seems very unattractive for Black.
30…Bh5 31.Kg3 Kg8
Black protects f7, perhaps hoping for …Bh5-e2 at some point.
32.f3!
Now Black’s Bishop looks more like a pawn and White has the queenside all to himself.
32…Kf8 33.Rb7 Ke8 34.a4!
34…Rb8
Not much better was 34…bxa4 35.Bxa4, with Rb7-b6 to follow.
35.Rc7 Nd8 36.Ra7! b4 37.a5!
A nice final touch! Here 37.Rxa6 bxc3 38.bxc3 Rb2 would allow Black back in the game. Now 37…bxc3 38.bxc3 Rb2 meets 39.Ba4+ Kf8 40.Bc5+, winning.
37…b3 38.Bd1, 1-0.
| 