It has been a common observation at amateur level that they tend to exchange almost equal value pieces whilst playing against stronger opponent, with a draw in mind. Sometimes, they just move mechanically based on general rules. This in fact, gives masters an opportunity to demonstrate their technique. Here is an instructive example:
In the given position, Black exchanged his knight against White’s bishop and went for a bishop vs. knight endgame. At first this looks quite innocent and even a good idea because we have been told that a bishop is usually better than a knight in the endgame against knight. Secondly the position is not so closed, so Black might be able to open the position & can change the pawn structure. Lastly, Black could emerge with a passed pawn on either c- or d-file.
But taking the bishop on d3 is actually a mistake because it has nothing to attack. And White’s knight would become very active on c3, d4 or f4.
Interesting Exercise: Change the position of the bishop from e8 to d8 and analyse the position! This kind of imagination is helpful in learning chess.
Question: How would you recapture on d3?
Answer: Recapturing with king is dubious due to 1…c5!. For example 1…c5! 2. Nc1 Bb5+ 3.Kd2 Bc4 from where the bishop can be exchanged against the knight almost by force, while pawns on c5 and d5 guarantees Black a better game.
In the game Alekhine played cxd3! and now c5 is rather dubious idea (compare it with the previous line 1. Kxd3)
1.cxd3 c5?! 2.d4! c4
2…cxd4 is even worse because of 3. Kxd4 Kc6 and 4. Kc5 is winning.
The pawn can’t be taken because of Nf4
Fixing a weakness, which is quite common in masters’ game!
Black tried to fight for next 20 moves but failed to change the outcome of the game.
Interesting Exercise: From here try to win the position against your friend or even an engine.