KEG: Post II
Chances were approximately equal after Mason's 25. c3, but from there the game went rapidly downhill for Brody. 23... Bf6
23...Rd8 was much better.
24. cxd4
Missing the chance to obtain an advantage with 24. Rd2 or perhaps 24. Rc2. 24... Bxd4
Black should have played 24...cxd4, though the complications would have been intense and he would have had to sacrifice the exchange: e.g., 25. Ba3 Rxe6 26. RxR QxR 27. BxR KxB. The position would then have been: 
click for larger view.
Black's Bishop pair and passed pawn provide adequate compensation for the lost exchange. One can certainly understand Brody's reluctance to go in for this line over-the-board. However, after the text (24...Bxd4, he gets into trouble. 25. BxB cxB
The position was now:
click for larger viewAs compared with the 24...cxd4 line, Brody has material equality, but a difficult game. In any case, he from her quickly ruined his chances. 26. Qd3 Qd6
27. Re5 Ba6
28. Qd2
28. Qd1 was slightly better.
28... Rf6?
This tangles Black's pieces and problems from which Brody never recovered. Either 28...Bc8 or 28...Rxe6 would have been much better. 29. Nc5!
This ends Brody's mating threats and allows Mason to dominate the board. 29... Bc8
30. Rfe2 Re7
31. Qd3
This left:
click for larger view31... Rf8
Rosenthal in the Tournament Book claims that Brody could have obtained an "equal game" with 31...Bxe6, but his analysis is badly flawed, After 31...Bxe6, Mason would have had the crushing retort 32. g4!. Even without this resource, Mason had a likely win with the simple 32. NxB (the only move Rosenthal considers) RfxN 33. RxR RxR and now--contrary to what Rosenthal suggests--White can win a pawn with 34. Qc4 Kf7 35. rxR QxR 36. Qc7+ Qe7 37. Qd4+ and 38. Qxd4. The text, though hardly pleasant, was probably Brody's best chance to save the game. 32. Rd2 Bxe6
33. Qxd4
Mason could have won more easily with 33. NxB, but the text is sufficient to win. 33... Qb6
Rosenthal is correct that 33...QxQ was far better here, but Mason could still have won after Rosenthal's 34. RxQ Kf7 because then would follow 35. NxB RxN 36. Rd7+ Ke8 37. Rxh7 RxR 38. FxR with a winning Rook endgame. Brody would have put up better resistance after 33...QxQ 34. RxQ Rfe8, though Mason would still probably have prevailed. After the text, as will be shown, Mason had a clear win. 34. Kh2 Rfe8
35. Rde2 Kf7
The position was now:
click for larger viewAs I will show in my next post, Mason had a clear winning line here. In fact he had two clear winning lines. Instead, he played a move praised by Rosenthal in the Tournament Book that could have put his victory very much in doubt with best play by Rosen (who in turn erred badly on his 40th move and lost soon thereafter). | 
Kibitzing
