|KEG: Post II
Obtaining a theoretically winning position is one thing. Being able to convert such an advantage and actually win the game is another. For quite a while in this game, Showalter had problems accomplishing the latter task.
White had many good plans at his disposal here (10. Bf4; 10. Qb3; 10. d5). The text, while not losing all of Showalter's advantage, was not among them.
Rosen apparently decided to play to trade off White's b3 Bishop for the thus far inactive Black Queen's side Knight. This plan, however, could have been easily countered, and 10...h6 or 10...Kg8 arranging for the protection of the Black King were better.
11. c5 was another good idea here, but the text which develops the dark-square Bishop was also good.
Continuing with his questionable plan. 11...Nc7 or 11...Kg8 were better.
Showalter should probably have made sure to preserve his Bishop with 12. Bb1, awkward as that looks. If he didn't fancy doing that, he should have played something more productive such as 12. d5. The text, which makes room for the Bishop to retreat without locking in the a1 Rook only works if Black fails to trade on his next move.
Given Rosen's 10...Na6 and 11...Nb4, it is hard to see why he didn't play 12...NxB here.
Once again, Showalter should either have preserved his Bishop with 13. Bb1 (especially since that move--thanks to Rosen's 12...h6) will not lock in his Rook). Alternatively, he should have played 13. d5.
Finally! His alternative here was 14. Ne5.
Once again, Ne5 was a reasonable alternative. But the text has the merit of driving away the pesky Black Knight at b4 and causing Black to lose time.
Now, after Rosen's ill-advised Knight venture, the position was:
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Showalter still has much the better position. But how should he continue:
This effort to pile up his heavy pieces on the e-file can't have been best. The Pillsburyish 16. Ne5 looks best.
Thanks to Showalter's dawdling, Rosen has managed to create a difficult but probably defensible position for himself.
16...Nc7 was another good alternative.
The alternative was 17. Ne5. In either case, Black is not without resource.
A poor and wasted move that deprives Black's King of possible refuge on h7. Better were 17...Nc7 (perhaps finally getting the a6 Knight into the game) or 17...Kh7.
There was no reason to ease Rosen's defensive burdens by this exchange. 18. Ba2 (exploiting the position of the Black King) or 18. Re3 (following up on his questionable 16. Rd3) were better.
19. Ne5 Nc7
20. f3 Ng5
21. Qd2 h5
21...Qf6 or 21...Kh7 were better.
Bringing this Knight to the King-side where it could have decided the game in White's favor (thanks to Rosen's poor 23rd move) in short order.
The position was now:
click for larger view
Showalter is still clearly better but Rosen is nonetheless hanging in there. At this point, however, Rosen erred allowing--as I will discuss in my next post on this game--a possible winning combination by Showalter.