Lessons From Prague III

ANYONE doubting the power of the bishop-pair should look at my round-three game.

White has just played 29.b3

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Stockfish17 and Dragon1 reckon the position is completely equal, which means the bishop-pair is compensating for Black being a pawn down and having three isolanis.

The game continued 29...Bb2 30.Rxc8 Rxc8 31.a4 bxa4 32.bxa4 Bd5 33.a5

White has a passed pawn, but the position remains equal

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Now 33...Ra8 puts immediate pressure on the passer. It can be defended with 34.Bb6, but then comes 34...Bc3. And after 35.Nf3 Black can give up the bishop-pair to snaffle the pawn by 35...Bxf3 36.gxf3 Bxa5 with complete equality as the pinning 37.Ra1?? is a gross blunder in view of 37...Bxb6+.

The game saw 33...Rc2?, when 34.Nf3 gains a probably decisive tempo on the light-square bishop.

However I played 34.a6?!, when 34...Bc1 again demonstrates the bishops' power, eg 35.a7 Bxd2 36.Bxd2 Be4 leaves White no way of converting the pawn advantage.

Instead 34...Bc3? should lose to 35.Nf3, but after 35.a7? the bishops could again prove their worth with 35...Bxd2 36.Bxd2 Be4, reaching the same drawn position as in the note in the previous paragraph.

However my opponent played 35...Ra2??, when 36.Nb1 wins a piece, but my inferior 36.Nf3?! was also good enough, and I won in a few moves.

So how much is a bishop-pair worth?

International master Larry Kaufman - now a grandmaster - wrote a famous article on The Evaluation Of Material Imbalances, using a database of almost 300,000 games involving players rated 2300+.

He concluded that the bishop-pair, ie having two bishops against bishop and knight or against two knights, is on average worth half a pawn.

But pay attention to the word average. On an open board the value of the bishop-pair rises, which is why in the first diagram the bishops compensate for Black being a pawn down and with pawn weaknesses.

LESSON: ignore the advantages of a bishop-pair at your peril. Kaufman even goes so far as to claim that "if you have the bishop-pair, and your opponent's single bishop is a bad bishop (hemmed in by his own pawns), you already have full compensation for a pawn."