The game between Fred Olson (1646) and me (1593) from the Edison (NJ) First Sunday of the Month Quad on May 4, 1975 presented many moments in which pawn tension could have been better handled.
Here is the position after my opponent played 10. f2-f4.
Having played 9...Rb8 as the first step in preparing the ...b5 break, Black should continue along this vein with 10...a6. If White played 11. a4 to inhibit that break and to open the file for White's a-rook in case that break were achieved nonetheless, the continuation might have been as shown in the next chess movie.
This PGN could not be parsed.
- move 4 could not be played: Invalid PGN : Error converting move Nd4
[fen "1r1q1rk1/pp1bppbp/2np1np1/2p5/2P1P3/2NP2PP/PP2NPB1/R1BQ1RK1 w - - - -"] 10. f4 a6 11. a4 Nd4 {White should probably develop by 12. Be3, when the game might go 12...Nxe2+ 13. Qxe2 b5 14. axb5 axb5 15. cxb5 Bxb5 16. Nxb5 Rxb5 17. d4 Qb6 18. dxc5 dxc5, and Black seems okay.} 12. Nxd4 cxd4 13. Ne2 {Trying to distract Black from his objective of playing ...b5, but to no avail.} b5 14. axb5 axb5 15. Nxd4 Qb6 16. Be3 Ng4 {A thematic tactic in the Dragon and similar Sicilians.} 17. hxg4 Bxd4 {If now 18. Bxd4 Qxd4+ 19. Rf2, then 19...bxc4 20. dxc4 Qxd1+ 21. Rxd1 Bxg4, regaining the pawn, yet retaining pressure.} 18. Bf2 bxc4 19. dxc4 Bxf2+ 20. Rxf2 Qc5 {Threatening 21...Rxb2 or 21...Qxc4.} 21. Qe2 Rb3 {Black has more than ample compensation for the pawn.}
Black actually played 10...e6 to prevent 11. f5, reckoning that the weakening of his d-pawn (not to mention the f6-square) could be withstood in a closed position. The fallacy was in believing that White wouldn't soon be able to expose Black's d-pawn, as will soon be apparent.
In the resulting position,
White played 11. Be3, and Black replied 11...Re8, a further prophylactic against f5... because after ...exf5, White's e-pawn would be pinned against the e-bishop. However, although f5... would have given White a space advantage on the kingside, this would hardly be decisive by itself, especially if Black promptly sought counterplay by preparing the ...b5 break. Moreover, neither 10...e6 and 11...Re8 is otherwise useful for Black, whereas both 10. f4 and 11. Be3 are useful for White. Finally, if White were to eventually play f5... and exchange at g6, Black's rook might be better placed at f8 than at e8.
After 11...Re8,
White could have played 12. d4, threatening to win material by 13. dxc5 dxc5 and either 14. Bxc5 or 14. e5 Nh5 15. g4, winning a piece. 12...b6 would protect the c-pawn adequately, but after 13. dxc5, recapturing with the b-pawn would allow 14. Qxd6, whereas recapturing with the d-pawn would again lose material after 14. e5. Therefore, Black would have to reply 12...cxd4 but would face difficulties as shown in the following chess movie.
This PGN could not be parsed.
- move 2 could not be played: Invalid PGN : Error converting move cxd4
[fen "1r1qr1k1/pp1b1pbp/2nppnp1/2p5/2P1PP2/2NPB1PP/PP2N1B1/R2Q1RK1 w - - - -"] 12. d4 cxd4 13. Nxd4 {Now 13...Qb6, threatening 14...Qxb2 or 14...Nxe4, would be met by 14. Ncb5!, shielding White's b-pawn and preparing the discovery 15. Nf5 to hit Black's d-pawn a second time.} a6 {Preventing 14. Ncb5 and intending 14...Na5 followed by ...b5, which would soon saddle White with a weak pawn on a half-open file.} 14. Nxc6 {Eliminating Black's soon-to-be troublesome knight and intending 14...bxc6 15. Qd2 followed shortly by b3..., which would help solidify White's queenside so that he could focus on Black's d-pawn.} Bxc6 15. a4 {So that Black's ...b5 break gives White an open file for his a-rook.} b5 16. axb5 axb5 17. Ra6 {Already benefiting from the opening of the a-file, the rook now skewers two un(der)protected units along the rank.} Qc8 18. Rxc6 Qxc6 19. e5 Qxc4 20. exf6 Bxf6 21. Ne4 Be7 22. Nxd6 Bxd6 23. Qxd6 {Material is about even, but Black will be hard pressed to prevent White from infiltrating the kingside via the dark squares.}
Black's difficulties can be largely traced to the pawn structure. Imagine that the game had instead gone 10. f4 a6 11. Be3 b5, bringing about the following position:
Suppose that to prevent 12...bxc4 followed by 13...Rxb2, White were to play 12. cxb5 axb5, and White then broke in the center by 13. d4, bringing about the following position:
Protecting Black's c-pawn by 13...Qb6 would invite 14. dxc5 dxc5 15. e5, which would attack the only defender of the d7-bishop. However, Black could reply 13...cxd4 without making his d-pawn vulnerable despite its being on a half-open file, because it would be held by Black's pawn at e7.
In retrospect, 10...e6 severely damaged Black's position by weakening his d-pawn.
In the game after 11...Re8,
the next move-pair was 12. Qd2 e5. White could now have bypassed by 13. f5.
This would be especially favorable for White because the center is locked. Had White played 13. f5, it would have revealed Black's 12th move to have rendered useless the prophylaxis from his two previous moves (which as noted earlier, shouldn't have been undertaken at all).
The continuation might be as depicted in the next chess movie.
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move f5
[fen "1r1qr1k1/pp1b1pbp/2np1np1/2p1p3/2P1PP2/2NPB1PP/PP1QN1B1/R4RK1 w - - - -"] 13. f5 Nd4 {Allowing the d7-bishop to support ...b5 and readying to trade one set of minor pieces, thereby diluting the strength of White's coming kingside attack.} 14. g4 {Not only expanding on the kingside but creating a spot at g3 for the e2-knight.} Nxe2+ {Eliminating the knight in question, before it can elude this exchange. Also hoping to stall White's attack after 15. Nxe2 gxf5 16. gxf5 Nh5, although this seems tenuous.} 15. Qxe2 {To meet 15...gxf5 with 16. g5.} 15...b5 {Prepared to meet 16. Bg5 with 16...h6 to break the pin before White can pile on the knight.} 16. Bf3 {Controlling the h5-square, hence threatening 17. g5. If now 16...b4, then 17. Nd1 would leave the center and queenside locked and stifle Black's counterplay. Or if 16...h6, then 17. h4.} 16...Bc6 17. g5 Nd7 18. f6 Bf8 19. h4 {Threatening to advance to the fifth rank and then open and double major pieces along the h-file. If Black tries 19...h5, then 20. Bxh5 gxh5 21. Qxh5 creates the winning threat 22. g6.} 19...h6 20. h5 hxg5 21. Bxg5 Nxf6 22. Bg4 Be7 23. Qf3 Nxg4 24. Qxf7+ Kh8 25. hxg6 {Black has no good defense to mate at h7.}
White actually played 13. Kh2, and the game continued as follows:
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Kh2
[fen "1r1qr1k1/pp1b1pbp/2np1np1/2p1p3/2P1PP2/2NPB1PP/PP1QN1B1/R4RK1 w - - - -"] 13. Kh2 {Not as incisive as 13. f5, but not bad.} 13...Nd4 {Now 14. f5 would entail sacrificing the pawn for unclear compensation.} 14. fxe5 {If now 14...Nxe2, then 15. exf6 Nxc3 (Forced, as two of Black's pieces were attacked.) 16. fxg7 Na4 (Dim on the rim, as is said.) 17. Bg5 Qc7 18. Bf6, and Black's kingside is wretched.} 14...dxe5
In the position reached in the above chess movie,
White should try to leverage the now half-opened f-file. This suggests the move 15. Bg5, pinning the knight as a target for further attack and threatening 16. Nxd4 (Clearing the second rank with tempo.) 16...cxd4 17. Nd5 Re6 18. Qf2 (Black has no additional units that can defend his knight.) 18...Ng4+ 19. hxg4 Qxg5 20. Qxf7+ Kh8 21. Qxd7.
After 15. Bg5, Black's best try seems to be 15...Nxe2, as White's recapturing with the knight would take that piece further from the d5-square, whereas taking with the queen would permit 16...h6 to break the pin. After 15. Bg5 Nxe2 16. Qxe2, 16...Ng4+ would lose a pawn to 17. Qxg4 (Intending 17...Bxg4 18. Bxd8, winning a piece.) 17...f6 (To regain the piece.) 18. Bxf6 Bxf6. 16...h6 also would lose a pawn, by 17. Bxf6 Bxf6 18. Qf2, hitting f6 and c5 and with a veiled attack at f7.
The game instead continued 15. Bxd4 cxd4 16. Nd5, bringing about the following position.
Black has an opportunity to activate his kingside majority by 16...Nxd5 followed (after either recapture) by 17...f5. Although the exchange of knights would give White a protected passed pawn, it's hard to imagine a scenario where it could safely advance. This is partly because White's e2-knight has hardly any safe moves, and several tempi would be needed to reposition it to an effective square, if there is one.
However, Black played 16...Bc6, with what intent I'm not sure.
Black continued to meander and eventually lost.
Moral: If you judge it necessary to impede the opponent from carrying out a pawn break or other plan, try to accomplish this by
1. Moves that would be desirable anyway (such as developing moves); else
2. Moves that serve no other purpose but at least don't create weaknesses that the opponent can exploit; else
3. Moves that give you exploitable weaknesses but nonetheless seem indispensable.
The above game demonstrates some of the difficulties that can result from disregarding this principle.
(A list of the threads I've initiated at this forum is available at http://www.davidlevinchess.com/chess/RHP_my_threads.htm .)