Imbalances: Bishop vs Knight

CM Christopher800
Apr 6, 2016, 5:42 PM |

In this blog post I'll be talking about an imbalance which is very important to understand yet not entirely understood by amateurs.
Which imbalance would that be? That would be the bishop vs knight imbalance. 

First lets go through the strengths and weaknesses of each piece.
The bishop is fast and can switch from one side of the board to the other in one move. However it suffers from the flaw of being stuck on one colour complex.
The knight can use both colour complexes but is a slow moving piece.

What are the consequences of such differences? 
This makes both bishops and knights very sensitive to intricacies of the pawn structure. Is the board open and many diagonals open? Then the bishop would do better than the knight.
If the position has closed pawn chains with closed diagonals then the knight does better than the bishop usually.
Of course there are exceptions but these rules are generally good ones to follow. 

Here is a basic diagram showing a bishop outperforming a knight in a pawn race.

Black is up two pawns and should win right? Nope it is White who wins thanks to the fact that his bishop supports the white passer and stops the black ones at the same time. The knight on the other hand is unable to do both at once. So in pawn races the bishop's advantage over the knight becomes very obvious.
Here is another diagram except this time the knight outperforms the bishop.

Here this position is even material but with White to move Black can resign. Why? The knight's ability to reach both colour complexes allows it to attack the pawns like a wolf set upon a herd of sheep while the bishop is powerless to intervene. After Nd4/a5 the knight now starts taking pawns starting with Nxc6. It is also worth mentioning that Black is also lost with the move because after 1...Bg7 2. Na5 Bc3 3. Nxc6 eats a pawn and defends b4 at the same time.