Ah! What a surprise...
In chess, like in life, the hardest blow is the one that comes unexpectedly. When one knows what to expect, he can prepare, adjust, adopt, defend, and can do many things to ease the blow. What do we call unexpected exchanges? I would think of it as trading a piece that has either more value or is better placed for a piece that is either inferior or passive. In our minds we have a set of rules that we learn as beginners in chess: put pieces in the centre, develop, castle etc., don’t give up pieces with higher value for the ones with lower value, etc. These rules help guide us through the game, save time, and narrow the choice of candidate moves. This way of thinking differentiates us from computers: the machines calculate every single possibility, while we limit ourselves to ones that are strategically correct. The thinking method has its downfalls, since it makes it hard to even consider a move that is ‘strategically incorrect’. When I think of unexpected exchanges, the first game that comes to my mind is Kamsky- Tiviakov, which we are going to explore as a first example.
It is white to move and Kamsky makes a move that loses a piece on the spot. How can a player of such a high caliber make such a horrible blunder? After Nd4 white probably only considered the knight moves for black. B:d4 has no positional grounds whatsoever: Bg7 is the strongest piece, it has the open diagonal a1-h8, it protects black’s king, and basically it is an ideal piece. Subconsciously, B:d4 was rejected without any calculations I suspect. Taking on d4 with the bishop is a pure tactical operation, a trick that black has to win a piece. It is easy to spot the trick once you consider B:d4, for Kamsky it would take 2 seconds. But all the strategical concepts that he learned before blocked him from seeing this unexpected exchange.
The next example is of a different nature. It is fairly typical Kings Indian structure: Black has an attack on the kingside, while white attacks on the queenside. It seems that black is ahead in his plan. White’s king is in trouble: black threaten Qh4 and white does not allow it with g3 then Nf2-Nh3 with a direct attack. Black finds a dynamic continuation that allows him to capture the initiative.
Black’s player is Larsen in the following position, he is known for unusual solutions to chess problems. This exchange is similar to Kamsky’s game but has a different idea behind.
In the next example, white was an extraordinary player, GM Bronstein. He was famous for his creative approach to chess: his ideas were bright, unusual, even sometimes incorrect, but never typical. In the position we will look at he found the right move, while many grandmasters might not find it. Nc5 is very strong: it attacks the weakness on e6, can be maneuvered to e5, limits black's pieces, and takes away b3 square. Ba6 seems to be a bad piece because central pawns are on dark squares and they limit it. However, after black plays Bc4, they would add control to b file, while totally cut white’s Bg2 out of play. Indeed, Bc4 would have great potential, keeping an eye on the e2 pawn while sometimes threatening Bb3, black would be doing very well. This is why Bronstein decided on this unexpected trade.
