01 May '23 15:23>
When one has a choice of recaptures, the one that also develops a piece is often superior. However, the ultimate justification for developing a piece is that from its new post, that piece would better support a player's middlegame plan than if the piece were on a different square.
How should one choose a sensible middlegame plan? First, look for a sector of the board where your pawns as a group are further advanced than the opponent's are. This gives you more space for pieces. Once your pieces are massed in that sector, you would seek to exchange at least one pair of pawns so that your superior forces could engage the opponent's.
The value of a space advantage conferred by the pawn structure is well-illustrated by the recent RHP game (Game 15188836) between MisterCat (1772) and TheBigKat (2338).
In the position
White has just played 19.Nx(N)h6. How should Black recapture?
That would depend on Black's middlegame plan. So, start by examining the pawn structure:
For each file, determine which side, if any, has more space along that file (where "space" means the number of ranks before encountering a pawn).
* a-file: no space edge for either player (1 rank up to each side's pawn).
* b-file: White has more space, with 6 ranks to Black's 1 rank.
* c-file: no space edge for either player (2 ranks up to each side's pawn).
* d-file: Black has more space, with 5 ranks to White's 2 ranks.
* e-file: no space edge for either player (3 ranks up to each side's pawn).
* f-file: Black has more space, with 2 ranks to White's 1 rank.
* g-file: Black has more space, with 3 ranks to White's 2 ranks.
* h-file: Black has more space, with 5 ranks to White's 1 rank.
Where is Black's space advantage most pronounced (that is, the greatest difference between the number of ranks available to Black and the number of ranks available to White)? This would be along the h-file, which gives Black 4 (5 minus 1) more available ranks than White has. Next-most pronounced would be along the d-file, where Black has 3 (5 minus 2) more available ranks than White has.
Black is already exerting pressure along the d-file (in fact, attacking White's pawn there), and this should be continued. In addition, Black should seek to open the kingside, where Black has much more space. This would entail creating pawn tension there, and then releasing it at the moment when Black's pieces could best profit from the resulting open lines.
What kingside pawn(s) can Black move so as to create tension?
Being that White's e-pawn is fixed for the moment at e4, advancing Black's f-pawn to to f5 would ensure the creation of pawn tension. The resulting pawn structure would be
If White were to play exf5... and Black were to recapture (with a piece), yielding the pawn structure
which side would benefit more?
To answer this, let's examine how this pawn exchange would affect each side's space in the e- and f-files. Along the e-file, White would now have 4 ranks to Black's 3 ranks. However, along the f-file, Black would now have 6 ranks to White's 1 rank. For the two files combined, Black would have 9 ranks of space to White's 5 ranks, a difference of 4 ranks. Before playing ...f5, Black had only 1 more rank of space along these two files combined. So, considering the pawn structure in isolation, it would appear that the exchange of pawns at f5 would favor Black.
Let us now examine the positions after Black recaptured at h6 and then played ...f5 (for the moment, disregarding White's intervening move). First, after 19...Bxh6 and 20...f5.
Thanks to 19...Bxh6, the f8 square is available to a Black rook (and the h-rook would be preferred, allowing the d8-rook to continue pressuring White's pawn on that file). But what is the bishop doing at h6? The c1/h6 diagonal is obstructed by Black's g-pawn. Moreover, this bishop had great mobility along the a3/f8 diagonal, where it might eventually have gone to c5 (to control the d4 square) or to a3 and then b2 (to attack White's c-pawn).
In contrast, here's the position after 19...Rxh6 and 20...f5.
Although the h-rook no longer has access to the f8-square, it can nonetheless reach the f-file (at the f6-square). The advantage of having the rook "leading" Black's major pieces along the f-file will become apparent in the game continuation, which includes a variation where Black threatens a White pawn at f3 only because Black's rook would be making the first capture at that square. Also, Black's bishop has retained the splendid a3/f8 diagonal noted above.
Finally, we'd need to consider how White's having a 20th move might change things. We will see this in the game continuation after 19...Rxh6 (which was actually played) in the following chess movie.
To sum up, that a move satisfies one or more principles is not sufficient reason to trust it. However, a move that violates one or more principles should be distrusted--by which I mean, not rejected outright, but examined with particular care.
(A list of the threads I've initiated at this forum is available at http://www.davidlevinchess.com/chess/RHP_my_threads.htm .)
How should one choose a sensible middlegame plan? First, look for a sector of the board where your pawns as a group are further advanced than the opponent's are. This gives you more space for pieces. Once your pieces are massed in that sector, you would seek to exchange at least one pair of pawns so that your superior forces could engage the opponent's.
The value of a space advantage conferred by the pawn structure is well-illustrated by the recent RHP game (Game 15188836) between MisterCat (1772) and TheBigKat (2338).
In the position
White has just played 19.Nx(N)h6. How should Black recapture?
That would depend on Black's middlegame plan. So, start by examining the pawn structure:
For each file, determine which side, if any, has more space along that file (where "space" means the number of ranks before encountering a pawn).
* a-file: no space edge for either player (1 rank up to each side's pawn).
* b-file: White has more space, with 6 ranks to Black's 1 rank.
* c-file: no space edge for either player (2 ranks up to each side's pawn).
* d-file: Black has more space, with 5 ranks to White's 2 ranks.
* e-file: no space edge for either player (3 ranks up to each side's pawn).
* f-file: Black has more space, with 2 ranks to White's 1 rank.
* g-file: Black has more space, with 3 ranks to White's 2 ranks.
* h-file: Black has more space, with 5 ranks to White's 1 rank.
Where is Black's space advantage most pronounced (that is, the greatest difference between the number of ranks available to Black and the number of ranks available to White)? This would be along the h-file, which gives Black 4 (5 minus 1) more available ranks than White has. Next-most pronounced would be along the d-file, where Black has 3 (5 minus 2) more available ranks than White has.
Black is already exerting pressure along the d-file (in fact, attacking White's pawn there), and this should be continued. In addition, Black should seek to open the kingside, where Black has much more space. This would entail creating pawn tension there, and then releasing it at the moment when Black's pieces could best profit from the resulting open lines.
What kingside pawn(s) can Black move so as to create tension?
Being that White's e-pawn is fixed for the moment at e4, advancing Black's f-pawn to to f5 would ensure the creation of pawn tension. The resulting pawn structure would be
If White were to play exf5... and Black were to recapture (with a piece), yielding the pawn structure
which side would benefit more?
To answer this, let's examine how this pawn exchange would affect each side's space in the e- and f-files. Along the e-file, White would now have 4 ranks to Black's 3 ranks. However, along the f-file, Black would now have 6 ranks to White's 1 rank. For the two files combined, Black would have 9 ranks of space to White's 5 ranks, a difference of 4 ranks. Before playing ...f5, Black had only 1 more rank of space along these two files combined. So, considering the pawn structure in isolation, it would appear that the exchange of pawns at f5 would favor Black.
Let us now examine the positions after Black recaptured at h6 and then played ...f5 (for the moment, disregarding White's intervening move). First, after 19...Bxh6 and 20...f5.
Thanks to 19...Bxh6, the f8 square is available to a Black rook (and the h-rook would be preferred, allowing the d8-rook to continue pressuring White's pawn on that file). But what is the bishop doing at h6? The c1/h6 diagonal is obstructed by Black's g-pawn. Moreover, this bishop had great mobility along the a3/f8 diagonal, where it might eventually have gone to c5 (to control the d4 square) or to a3 and then b2 (to attack White's c-pawn).
In contrast, here's the position after 19...Rxh6 and 20...f5.
Although the h-rook no longer has access to the f8-square, it can nonetheless reach the f-file (at the f6-square). The advantage of having the rook "leading" Black's major pieces along the f-file will become apparent in the game continuation, which includes a variation where Black threatens a White pawn at f3 only because Black's rook would be making the first capture at that square. Also, Black's bishop has retained the splendid a3/f8 diagonal noted above.
Finally, we'd need to consider how White's having a 20th move might change things. We will see this in the game continuation after 19...Rxh6 (which was actually played) in the following chess movie.
To sum up, that a move satisfies one or more principles is not sufficient reason to trust it. However, a move that violates one or more principles should be distrusted--by which I mean, not rejected outright, but examined with particular care.
(A list of the threads I've initiated at this forum is available at http://www.davidlevinchess.com/chess/RHP_my_threads.htm .)