In GM John Emms' More Simple Chess, he talks about transition squares, eg. a3 on a knight's route from b1 to c4. In GM Jacob Aagaard's Attacking Manual 2, he attaches some importance to this concept, recommending that if you have a hole on your third rank, you should be careful not to allow your opponent's knight access to any transition squares en route to that outpost. For instance, in the following game, GM Danielsen saw 25...Rc4 as his critical mistake allowing White to exchange, and get access for his knight to e4.
IM Mark Dvoretsky talking about 'transit squares:'
Emms' original idea was that a transition square was on the edge of the board, and that the piece would be out of play until it could be brought back. Aagaard includes central squares where the knight might be fulfilling important roles such as attacking pieces or pawns before moving on to other tasks. For Dvoretsky, there seems to be the idea that there is a narrow path through to the enemy's side of the board, but a hole that allows one through to occupy outposts, carry out exchanges, etc.
In GM John Emms' More Simple Chess, he talks about transition squares, eg. a3 on a knight's route from b1 to c4. In GM Jacob Aagaard's Attacking Manual 2, he attaches some importance to this concept, recommending that if you have a hole on your third rank, you should be careful not to allow your opponent's knight access to any transition squares en route to that outpost. For instance, in the following game, GM Danielsen saw 25...Rc4 as his critical mistake allowing White to exchange, and get access for his knight to e4.
IM Mark Dvoretsky talking about 'transit squares:'
- http://www.chesscafe.com/text/dvoretsky121.pdf
Emms' original idea was that a transition square was on the edge of the board, and that the piece would be out of play until it could be brought back. Aagaard includes central squares where the knight might be fulfilling important roles such as attacking pieces or pawns before moving on to other tasks. For Dvoretsky, there seems to be the idea that there is a narrow path through to the enemy's side of the board, but a hole that allows one through to occupy outposts, carry out exchanges, etc.