17.e5. It seems to me the diagonal the bishop was already on was a useful one. Even though the knight got a good square after 17.e5, the LSB got a very handy diagonal. +++++++ Just out of curiosity, I had a look at the rook sac - 17.Rxf6. After 17...gxf6 18.Qg4ch Kh8 19.Qh4 Qc6 (covering f6) 20.d5! (...Qc5ch 21.Kh1 Qc3 22.Ne2!! ... with the idea [A] 22...Qxa1 23.e5! Kg8 24.Qh6! and Black's game falls apart; or [B] 22...Qe5 (best) 23.Rb1 ... threatens 24.Bb2. Seems that 17.Rxf6 was good for the win, as well.

As White was threatening, among other things, 18.Rxf6, maybe 17...Nbd7 came into consideration.

Pin it and win it. Though 18.Rxf6 wins, why go for complications when a simple win is available? Another reason for Black to have tried ...Nbd7, by the way.

Considering there is no great discrepancy in material, and Black's pieces are reasonably active, White's central phalanx, two bishops on raking diagonals, and the initiative spell 'busted' for Black.

!? A very thematic sacrifice that is common to these positions. Of course the computer sees that lines that just crush black into the ground without needing to sacrifice, cause computer's are greedy piece gobblers, but this still seems great.

I have mentioned Rxf6 once or twice already, and it wins here, but how about 20.Bxf6 gxf6 21.Nf5 ... for the win? Black would have to give up the queen to hold off the mate. If Black doesn't take the bishop, it participates in the further attack. In some lines, the WQ moves onto the long diagonal at b2, the square vacated by the bishop.

There are no good moves. This just brings the end a whole deal closer.

Computer's just have this way of properly slowplaying these positions. Get everything attacking and then break open and win the game. Also can I note that white is really playing against the Knight on a5, the Bishop on b7 and the Rook on a8. It is almost as if black is 3 pieces down, which is probably the reason the computer gives some of the lines +12 to white or so...Pawn+Knight+Bishop+Rook=12 point advantage.

21.Nf5! for mine, threatening an instant mate that forces Black to give up the queen to avert.

The alternative got axed by 26...Kf8 27.Qd6ch etc.