Perhaps Santasiere reasons, "If it worked for Marshall, then why not for me?" The game now follows almost exactly the earlier game Santasiere-Marshall, which Black won. In a sense, Santasiere is challenging Marshall to play against himself....
Santasiere perhaps wants to know if he should have grabbed the a-pawn in his game as White against Marshall in the identical position. Only Marshall can say...
...and Marshall answers "No." But 14.Bxa7 is certainly unclear. Perhaps Black should then play 14....Qe5 15.Qxe5 (the threat was mate at h7, and if 15.f4? Qxe2 16.Nxe2 b6! traps the Bishop) 15....Bxe5 16.Be3 Bxc3 17.bxc3 with targets of attack for both players.
This exchange probably helps Black more than it does White since the Black Rooks now double on the d-file, after which White must oppose Rooks and allow wholesale exchanges. But White loses after 15.Nd4? Bxh2+! (a bolt from the blue) 16.Kxh2 Qe5+ 17.f4 (better may be 17.Kg1 but Black is better all the same after 17....Rxd4! =+) 17....Qxe3! 18.Qxe3 Ng4+ 19.Kg3 Nxe3 and Black is winning.
Here Marshall had played the immediate 18...Nd5! to help preserve winning chances by keeping one pair of Rooks on the board. Santasiere's willingness to exchange off all of the heavy pieces signals his willingness to run for the draw against the grandmaster.
Though the pawn at e6 is isolated and a potential liability, it does have the advantage of supporting Black in the center. In Queen and minor piece endings, the Queen and Knight combination is generally superior to the Queen and Bishop since the Knight can help the Queen to attack on various colored squares. Black, therefore, may have slightly the better of it in this position -- all the more reason that White should not have gone in for the exchange at move 15.
Clearly Black was satisfied with a draw, otherwise he might have kept the Knight on the board. Marshall is certainly averse to taking any risks since a draw will bring him a guaranteed first prize in the tournament.
21. Qxe3 Qxc2
22. Qxe6+ Kb8
23. h3 Qc1+
24. Kh2 Qf4+
25. Kg1 Qc1+