A few days ago I was watching a game played between Neiksans (2567) and Geir Sune (2453). On move number 20 white sacrificed his bishop for 2 pawns on a6. After a long thought I came to the conclusion that white wanted to create a pawn mass on the ‘b’ and ‘c’ files. Then on move 28 Black played …Rb8 and white rejected the exchange of rooks and played Rxf7. At first glance it looks dubious to exchange the last major and active piece, but White had very logical reasons for not exchanging the rook.
So why did White not exchange the rook?
1) It is last major piece on the board.
2) The rook is very active on 7th rank and has targets.
Eventually game was ended in a draw after 64 moves.
I was watching this game on Playchess and doing a ‘guess the move’ exercise (this is exciting and fun while doing it with a live game). I toyed with the idea of playing Rxb8 on move 29 with following considerations:
1) Black Knight on g3 is awkwardly placed so you can get tempo with e4 after Rxb8.
2) With the e4 lever you can create a strong pawn mass.
3) Black’s Rook is not participating in the main battle area.
Out of curiosity I checked my analysis with Fritz, where the engine didn’t like my moves at first, but after few moves it liked White’s position. I will not publish my analysis here as I want readers to do it on their own.
1) Like any tactical shot, the strength of a pawn mass must be analysed thoroughly.
2) A pawn mass is very powerful if it creates space for you and cramps opponent position, creates a mating net or the opponent has difficulty in bringing his pieces or additional piece into the action because of it.
This lesson is based on my experience; spend some more time on a move which looks dubious and illogical at first glance. Often you will find the logic in it after further study.