Chess School Quiz Challenge #2

Challenge

Grandmaster Frederik Svane has to capture the bishop on e4, otherwise he's a piece down. That much is clear. But how should he take the bishop?

Solution

Let's first count material and realize that White is a pawn up. Ergo: If anyone wants to win here, it's White. 

Generally speaking, we're happy to exchange material, to simplify things if we're up in material. According to this rule of thumb, 35.Qxe4 would be a good idea to exchange queens and turn the game into a bishop ending. 

But despite this rule of thumb, another factor plays a decisive role here: opposite-colored bishops, a white-squared one for White and a black-squared one for Black. In the endgame, opposite-colored bishops act as drawing factors. 

If the queens were exchanged, Black could, for example, place his pawns on black squares. There they would be unassailable for the white bishop. Or he could block a white passed pawn on a black square with his king and White could not drive it away from there. The passed pawn would be stopped. Often in the endgame not even two extra pawns are enough to win when there are opposite-colored bishops on the board. 

35.Qxe4 would be a mistake. Black would be only too happy to exchange queens. He would easily draw the ending thanks to the opposite-colored bishops despite being a pawn down. 

That's why Frederik Svane went 35.Bxe4 in this game of the opening round of the German Masters 2023 against the eventual tournament winner Dennis Wagner, a move he could have just come up with by eliminating 35.Qxe4 with drawn endgame.

There is another argument in favor of taking with the bishop: the lack of black king safety. Have you noticed the gaping hole in the black castling position? The black king is out in the open. In the endgame, with greatly reduced material, that wouldn't be a bad thing, the king would be under no threat. With queens on the board it could be different, White may be able to build up threats against the exposed black king. 

This leads us once again to the opposite-colored bishops, which are an ambivalent matter. In the endgame they act as drawing factors, in the attack they help the attacker, who often plays with an extra piece thanks to the opposite-colored bishops. If White were to succeed in staging an attack against the black king on the white squares, Black would find it difficult to defend these squares. He would have the wrong bishop for that.