dzechiel: White to move (25?). Material even. "Medium."
Sorry to get a late start, but my family took me into Los Angeles last night to see a play, and we didn't get home until very late.
Looking at today's position, it seems obvious that white needs to open the g-file in order to get the attack up to speed. The first thought is 25 Nh6+ as this is very forcing, however after 25...gxh6 26 gxh6+ Bg6 it appears that white has now self blocked the h-file and the attack will run out of steam.
So, it seems that the right way to sac the knight is
25 Nf6+
Now black has five legal replies (some better than others):
- 25...Kh8
- 25...Qxf6
- 25...Rxf6
- 25...Kf7
- 25...gxf6
Let's deal with them. The worst of the bunch is
25...Kh8 26 Qxh7+ Qxh7 27 Rxh7#
Only somewhat better is
25...Qxf6 26 gxf6
and black is down a queen with a lousy position. Then there's
25...Rxf6 26 gxf6
and black is down an exchange and still has a lousy position.
25...Kf7
OK, this is a much better try. It looks like the black king will make a run for it, how can white take advantage?
26 g6+
White gets in a little zwischenzug before moving the knight to h7. Black can move the king or take with the h-pawn, but g5 is now available for the white rook. Let's try
26...hxg6 27 Nh7
On the black rook.
27...Rh8 28 Rg5
and black will go down a queen for a rook. OK, lastly there's the move that makes it all interesting
25...gxf6 26 gxf6+
Once again black has several legal moves:
26...Qg6 or 26...Bg6 allow 27 Qxh7#
26...Kf7 27 Rg7#
26...Qg5 or 26...Qg4 allow the rook capture with check. Ugh.
26...Kh8 27 Qh6
This was the hard move to find IMHO. The threat is 28 Qg7#. The only good way to stop this is
27...Rf7 28 Rg7
Now the threat is 29 Qxh7+ Qxh7 20 Rxh7#. I think at this point that black has to give up the queen with
28...Qxh3 29 Qxh3 Rxg7 30 hxg7+ Kxg7 31 Qxe6
on the bishop and the d-pawn. I think the advanced black pawns will fall like ripe apples and white will win in the endgame.
At any rate, it's well beyond time to check.
Kibitzing
sac: 25.Nf6+
