Move 21

[WMHalsdorf]

[QUOTE=Brian-E;404972]If you could write down the line(s) you have in mind, we could verify this.[/QUOTE]
Upon further examination I found an improvement on that line.
21...f5 22.exf5 Ne5 23.Nxe5 Bxe5 24.Qh3 gxf5 25.Bd1 Rxb6. I had delayed playing Rxb6 trying to keep both rooks when in fact I should be simplifying our attack on the queenside which reduces their ability to attack on our king.

[Brian-E]

[QUOTE=WMHalsdorf;404986]Upon further examination I found an improvement on that line.
21...f5 22.exf5 Ne5 23.Nxe5 Bxe5 24.Qh3 gxf5 25.Bd1 Rxb6. I had delayed playing Rxb6 trying to keep both rooks when in fact I should be simplifying our attack on the queenside which reduces their ability to attack on our king.[/QUOTE]
Thanks, but I still assess that as a dangerous attack for White whose a1 rook can swing to the kingside via a3. One way you could convince me otherwise would be to show us your line which leads to perpetual check. (If we can force a draw, I rather think we should do so.)

[WMHalsdorf]

This what I've been kicking around with at this point, many of the lines can be improved by either side because it is intended to get a feel for the position

[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[ECO "A57"]
[Opening "Benko gambit half accepted"]

1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. b6 Qxb6 6. Nc3 g6 7. Nf3 Bg7 8. e4 O-O
9. Be2 d6 10. O-O Nbd7 11. Nd2 a5 12. a4 Ba6 13. Nb5 Rfb8 14. Nc4 Qd8 15. Qc2
Ne8 16. Bd2 Bxb5 17. axb5 Nc7 18. Bxa5 Qc8 19. b6 Nb5 20. Bg4 Nd4 21. Qd3 f5 (
21... Qe8 22. Qh3 Ne5 (22... f5 23. exf5 Ne5 24. Nxe5 Bxe5 25. fxg6 Qxg6) (22...
Nf6 23. Bc3 (23. f3 Nb3 24. Ra3 Nxa5 25. Rxa5 Rxa5 26. Nxa5 Rxb6) 23... Nxg4 24.
Qxg4 Qb5) 23. Nxe5 Bxe5 24. Bd7) 22. exf5 Ne5 23. Nxe5 Bxe5 24. Qh3 (24. fxg6
Qxg4 25. gxh7+ Kg7) (24. Bh3 gxf5 25. f4 Bf6 26. g3 (26. Ra3 Qa6 27. Qd2 Qc4 28.
Re1 Nb3 29. Qe2 Qxe2 30. Rxe2 Nxa5 31. Bxf5 Nc4 32. Rxa8 Rxa8 33. b7 Rb8 34. Bc8
Na5)) 24... gxf5 (24... Nxf5 25. Ra2 Qf8) 25. Bd1 Rxb6 26. Qh5 (26. Qh4 Bf6 27.
Qh5 Rba6 (27... Bg7 28. Ra3 Rba6 29. Rh3 h6 30. Rg3 Kh7 (30... Rxa5 31. Qxh6 Qf8
)) 28. Ra3 Qf8 29. Rh3 (29. Rg3+ Kh8 30. Rh3 Qg8 31. Rg3 Bg7 32. Bc3 Ra1 (32...
Qxd5 33. Rh3 Qg8 34. Bb3 Nxb3 35. Bxg7+ Qxg7 36. Rg3 Qf6 37. Rh3 Qg7 38. Qxf5)
33. Bxd4 cxd4 34. Be2 Rxf1+ 35. Bxf1 Rf8 36. Bd3 f4 37. Rh3 h6 38. Bf5 Rf6 39.
Rf3) 29... Qf7 30. Qxf7+ Kxf7 31. Bc3 Rh8 32. Bh5+ Kf8) (26. Ra3 Rba6 27. Qh5
Bg7 (27... Qf8) 28. Rh3 h6 29. Bc3 Qf8 30. Rg3 (30. Bxd4 Bxd4 31. Rg3+ Kh7 32.
Bc2 Be5 33. Bxf5+ Kh8 34. Rh3 Bg7 35. b3 Ra1 36. g4 Rxf1+ 37. Kxf1 Ra1+ 38. Kg2
Rd1 39. Qg6 Qf6 40. Qe8+ Qf8) 30... Qf6 (30... Kh8 31. Bxd4) 31. Rg6) 26... Rba6
27. Ra3 (27. Qg5+ Bg7 28. Ra3 (28. Qxe7 Rxa5 29. Rxa5 Rxa5 30. Qxd6 Ra6 31. Qe7
Re6) 28... Rxa5 29. Rg3 Qf8) 27... Rxa5 (27... Bg7 28. Rh3 h6 29. Bc3 (29. Rg3
Qf8 (29... Rxa5 30. Qxh6 Qf8 31. Qg6) 30. Qxh6 Qf6)) 28. Qg5+ Bg7 29. Rg3 Qf8 *

[Brian-E]

Removing the subvariations from the above, we have the main line 21...f5 22.exf5 Ne5 23.Nxe5 Bxe5 24.Qh3 gxf5 25.Bd1 Rxb6 26.Qh5 Rba6 27.Ra3 Rxa5 28.Qg5+ Bg7 29.Rg3 Qf8.

This position I would assess as won for Black. White is a piece down and the attack has run out of steam.

But my preferred move at the moment on general principles is 21...Qe8.

WMH, are you currently in favour of 21...f5? If so, please say so and I'll try to find more concrete objections than my vague "general principles".

[WMHalsdorf]

I haven't exampled Qe8 enough at this point to say if it is better than f5.
For Qe8 we have 21.Qh3 Nf6 22.Bf3 Qb5 which is one of our goals on the queen-side and 21.BxN QxN which gets white nothing. This leaves 21.Bc3 which needs to be examined in depth with qyestion will giving back the pawn get white enough play on the queen-side to win.

[Brian-E]

Regarding your last sentence, 21...Qe8 22.Bc3 Nxb6 23.Rxa8 Nxa8 I would assess as a slight advantage to Black. We have the queenside play here thanks to our play down the b file and active bishop and d4 knight (only one of which their c3 bishop can remove). I don't believe White should just return the pawn so easily. That pawn on b6 is a cramping influence on our play there.

I need to ask you a question: on what strategic grounds do you think we should be considering the move 21...f5? To me it is weakening and unnecessary. But if you can indicate why you think it might be a useful move, then that gives me motivation to look at it on strategic grounds.

[WMHalsdorf]

[QUOTE=Brian-E;405082]Regarding your last sentence, 21...Qe8 22.Bc3 Nxb6 23.Rxa8 Nxa8 I would assess as a slight advantage to Black. We have the queenside play here thanks to our play down the b file and active bishop and d4 knight (only one of which their c3 bishop can remove). I don't believe White should just return the pawn so easily. That pawn on b6 is a cramping influence on our play there.

I need to ask you a question: on what strategic grounds do you think we should be considering the move 21...f5? To me it is weakening and unnecessary. But if you can indicate why you think it might be a useful move, then that gives me motivation to look at it on strategic grounds.[/QUOTE]
If you feel that your assessment of the position favors us then Qe8 would be a better choice since f5 is far more complicated which I think I mentioned before. Any thoughts davar55?

[Brian-E]

[QUOTE=WMHalsdorf;405085]If you feel that your assessment of the position favors us then Qe8 would be a better choice since f5 is far more complicated which I think I mentioned before. Any thoughts davar55?[/QUOTE]
Just to be clear: I [U]don't[/U] assess the position as favourable to us at all. Nor do I shy from complications. I just want to know what strategic justification you have for considering 21...f5, because I simply don't understand what we achieve from it.

Like you, I too urge davar55 to chip in again.

[WMHalsdorf]

I am looking for move that forces white to commit the their queen to king-side both Qe8 and f5 do exactly that, the problem is which is more effective. The only probel I have right now is how to proceed after 21... Qe8 22.Nxd7 Qxd7 this position is unclear in that white has options.

[Brian-E]

[QUOTE=WMHalsdorf;405161]I am looking for move that forces white to commit the their queen to king-side both Qe8 and f5 do exactly that, the problem is which is more effective. The only probel I have right now is how to proceed after 21... Qe8 22.Nxd7 Qxd7 this position is unclear in that white has options.[/QUOTE]
Thanks.

The way I see it, 21...f5 creates serious central and, especially, kingside weaknesses. White can open our g file with 22.exf5. And if we don't succumb to a kingside attack, we'll also have the hole on e6 to deal with later.

After 21...Qe8 22.Nxd7 Qxd7 White does indeed have various continuations to choose from. But a kingside attack is not really on the cards here for them because our kingside has no weaknesses and they have relinquished their light squared bishop. We have a well placed knight and pressure against b2. Against that, we are a pawn down, and a particularly unpleasant pawn that is too (the b6 pawn)! But 21...f5 doesn't solve that either.

Where do we disagree at the moment?

davar55, [U]please[/U] post your comments again too! The discussion has advanced since you expressed a preference for 21...Qb7, and neither WMH nor I are advocating that move now. We are nearly out of time, and we need your input.

[WMHalsdorf]

With f5 the knight on d7 can proceed to e5 and removes the knight that is defending both pawns on the b file. What ever attack the mount on the king-side can be met.