Game analysis - Understanding the potential of this queenside expansion From the game Samuel Reshevsky vs Henrique Mecking in the Sousse Interzonal (1967).

[fen "r2qnr2/1pnb1pbk/3p2pp/p1pPp3/2P1P2N/PPN1B1PP/3Q1P2/1R2RBK1 w - - 0 1"]

1.Na4 Na6 2. Rec1 Rb8 3.Nc3 Nf6 4.Qb2 Rg8 5.Qc2 Re8 6. Nb5 Bf8 (6... Bxb5 7.cxb5 Nc7 8.b4 axb4 9. axb4) 7. Bd2 b6


According to Reshevsky in his book "Art of Positional Play" black wants white to abandon his calm queenside expansion, so black forces white to play on the kingside. I suppose the queenside expansion was seriously dangerous as black decided to risk so much by playing ... f7-f5.

In the case of white passivity on the kingside, what sequence of moves could best represent the queenside expansion as winning the game for white? Using the computer help I imagined something like this: 21.Na4 Na6 22. Rec1 Rb8 23.Nc3 Nf6 24.Qb2 Rg8 25.Qc2 Re8 26. Nb5 26...Bf8 27. Bd2 b6. And here I believe that white fixed the queenside to his advantage. And if 26...Bxb5 27.cxb5 Nc7 28.b4 axb4 29. axb4 it is easier to see the rooks getting into action.

Are there better lines?
I am not trying to be hard on you, but to be blunt, this is one of the dangers of analyzing with a computer, and not having any understanding of the position. That line of analysis you give with 20...Nac7 and then shuffling around the pieces, frankly, did not make any sense at all plan-wise (and even my Stockfish 11 does not agree with your computer's line). I will discuss that in my notes to the game.

I opened my copy of that book, and what Reshevsky, correctly, said was that white has move space on the queenside, and that black needs to look for play on the kingside with f5. White's play, in theory, is generally  better, but what Reshevsky also said is that if white blindly pursues his own play on the queenside without any regards to his own king, he can easily lose to a direct attack. That is a common theme in the KID, especially the Classical variation. I have seen many games where white has a Na8, and is up a rook, but is helpless against the mating attack all the way on the other side of the board.

Here are Reshevsky's own words:



Reshevsky chose to play a line that he was well-prepared for f5, and then actually chipped away at f5, weakening e4, which led to the black king. In the vast majority of KID games, that is not the typical line of play, and white does not often get to be that active on the kingside. In most, white owns the queenside, and black owns the kingside, and each side tries to open their dominate side of the board. In most cases, going passive on your better side, and trying to just defend the other side where your opponent is better, is a recipe for a loss.

 [Event "Interzonal-07"]
 [Site "Sousse"]
 [Date "1967.11.02"]
 [Round "14"]
 [White "Reshevsky, Samuel Herman"]
 [Black "Mecking, Henrique"]
 [Result "1-0"]
 [ECO "E96"]
 [PlyCount "141"]
 [EventDate "1967.10.16"]
 [EventType "tourn"]
 [EventRounds "23"]
 [EventCountry "TUN"]
 [FEN ""]

 1. d4 Nf6 2. c4 d6 3. Nc3 g6 4. e4 Bg7 5. Be2 O-O 6. Nf3 e5 7. O-O Nbd7 8. Re1 a5 9. Bf1 c6 10. Rb1 Re8 11. d5 Nc5 12. b3 Na6 13. a3 c5 14. Bd2 Rf8 15. g3 Bg4 16. h3 Bd7 17. Bg5 h6 18. Be3 Ne8 19. Qd2 Kh7 20. Nh4 f5 (20... Nac7 {This gives up on slowing down white's play with b4, and from c7, the knight has no where to go. b5 might be an idea in some positions with the Ra8 on b8, but here b5 just loses a pawn.} 21. Na4 {The knight does nothing here, unless black cooperates and takes it. It also makes it harder to play b4, opening the queenside.} (21. b4 {This is not the best move per the computer, but it is the most natural, and leads to a solid static positional advantage immediately.} axb4 22. axb4 {+.75 depth 30, and the computer wants to pitch a pawn here with Na6.} Na6 23. bxc5 Nxc5 24. Bxc5 dxc5 25. Rxb7 Nd6 26. Rb3 $16) 21... Na6 {And it comes back.} (21... Bxa4 $2 22. bxa4 $16 {Doubled pawns, or not, white has huge pressure down the b-file.}) 22. Rec1 {Not an useless move, but how do you get in b4, opening the position?} Rb8 23. Nc3 Nf6 $2 {Blocking the move f5 cannot be right. Black will need that soon enough, but to be honest, I am not sure how to get it in anymore. If f5 is ruled out, then this knight probably belongs on c7, aiming for b5.} 24. Qb2 $2 {There is no point here since it cannot help with b4, or help stop b5 by black, and putting the queen on the same diagonal as the Bg7 unless there is a super reason, it probably also not a good idea.} Rg8 $2 {Again, no the right square to help any eventual f5 move. This is just a move that the computer things does not upset any balance, but it is not right.} 25. Qc2 {And back for no particular reason.} (25. Kh2 {This excellent waiting move could have been played at any number of moments.}) 25... Re8 {Still not the right square.} 26. Nb5 (26. Kh2 Nc7 27. Nf3 b5 $6 (27... b6) 28. b4 $1 $16) 26... Bf8 (26... Bxb5 $2 27. cxb5 Nc7 28. b4 axb4 29. axb4 $16) 27. Bd2 b6 {White does not want the queenside "fixed"...he wants it opened so the major (heavy) pieces can penetrate, and do damage.}) (20... Rb8 {If black is determined to be totally passive and only play on WHITE'S queenside (white is stronger there), this is the way preparing b5.} 21. Kh2 Nec7 {The Na6 stops b4, while the Rb8, Nc7, and Bd7 prepare b5, an action against b3 eventually. This is not destined to work, in my opinion.}) 21. exf5 gxf5 22. f4 e4 23. Bf2 Nf6 24. Nd1 Ng8 25. Ne3 Qf6 26. Bg2 Rae8 27. Qe2 Ne7 28. g4 Kg8 29. Bg3 fxg4 30. hxg4 Ng6 31. Nhf5 Bh8 32. Nxh6+ Kh7 33. Nhf5 Kg8 34. Nh6+ Kh7 35. Rf1 Qc3 36. Nef5 Bg7 37. Rbc1 Qxb3 38. Rb1 Qxa3 39. Rxb7 Nb8 40. Nxg7 Qxg3 41. Nxe8 Nxf4 42. Rxf4 Qxf4 43. Nxd6 Kxh6 44. Nxe4 Bxg4 45. Rb6+ Kh5 46. Qe1 Nd7 47. Ng3+ Kh4 48. Qe7+ Rf6 49. Qh7+ Kg5 50. Ne4+ Qxe4 51. Qxe4 Rxb6 52. Qe3+ Kg6 53. Bh3 Bxh3 54. Qxh3 Ne5 55. Qe3 Kf5 56. Qxc5 Rb1+ 57. Kg2 Rb2+ 58. Kf1 a4 59. d6 Rd2 60. Ke1 Rd4 61. Ke2 Ke4 62. Qa3 Rd3 63. Qb4 a3 64. c5+ Kf5 65. Qa4 Ke6 66. Qa8 Rb3 67. Qg8+ Nf7 68. Qg6+ Ke5 69. Qxf7 a2 70. Qa7 Rh3 71. d7 1-0