A second look at the Nolot positions
Feng-Hsiung Hsu
># Move: W
>
>r..qk..r Smaguine - Sahovic, Bienne 1990
>ppp.b.pp White wins with a queen sac but black has several ways to defend
>..n.p... 12.Nxg5!! Bxd1 13.Nxe6 Qb8 14.Nxg7!! Kf8 15.Bh6! Bg4 16.0-0+
>...pP.n. 17.Kg8 17.Rf4 +-
>...P..b. It should take between a few months and a few years for a program
>..PB.NN. to find 12.Nxg5!!
>PP....PP
>R.BQK..R
We took a closer look at this position. 12. Ng5 is a sound positional
sac, but depending on the temperament of the player, it might not be
the best move. The published annotation gives 12. Bg5 Bg5 13. o-o as
+=, but white could play 13. h3 instead and white appears to have a simple
positional squeeze. The critical line in the 12. Ng5 variation turns out
to be 12. Ng5 Bd1 13. Ne6 Qb8 14. Ng7 Kd8 15. Kd1. Black's queen and rooks
are temporarily out of play, black is up a pawn, but white has a protected
passed pawn, and lots of pressure. (The annotator gave one line that
ended "with the attack":). From DT-2's point of view, The Bg5 line was
gaining 0.20 pawn after each iteration, and so was the Ng5 line. Except
that the Bg5 line has about a 0.20 pawn lead at the same depth. There
appears to be no kill in the Ng5 line when black king goes to d8
instead of the f file. Black would have to give up the extra pawn to
activate the queen and the rooks, and while white is definitely better, black
is not without counter play. On the deepest search that we checked out,
black's evaluation stopped dropping at around -1.4 pawns, and black's pieces
were becoming active.
># Position: 6
># Move: B
>
>rnbqk..r Malaniouk - Ivantchouk, Moscow 1988
>.p...ppp 13... axb5!! offers a rook to keep the white queen out of
>p....... play. 14.Qxa8 Bd4 15.Nxd4 cxd4 16.Qxb8 0-0! 17.Ke1 Qh4
>.NpPp... 18.g3 Qf6 19.Bf4 g5? (Ivantchouk would have won much faster
>QPP.P.n. had he found 19...d3!, a move he found during the analysis.
>P....N.. Tasc R30 inds 19...d3! in 2 1/2 hours. But to find 13...axb5
>....KbPP it would probably need a couple of centuries...) 20.Rc1 exf4
>R.B..B.R 21.Qxf4 Qd4 22.Rd1 bxc4 23.e5 Qc3+ 24.Rd2 Re8 25.Bxd3 cxd3
> 26.0-0 Nxe5 -+
>Last minute info from Pierre, 19...Bf5!! is even stronger than d3
>What does DT think about move 19 for black, and in how much time, asks Pierre.*
First, 19. ... Bf5 was played instantly (at 6 ply) by both DT-1 and DT-2,
and within 30 seconds, both thought that black is winning big.
A interesting line is instead of playing 17. Ke1 as in the game, playing
17. c5!?. Black's attack looks menacing, but there is no obvious win.
13. ... ab5!! seems clearly the best move in the position, even though
Ivanchuk did not see all the complications over the board, and we cannot
establish that it necessarily wins. It probably would tie down the
machine for a few days to find the move. Perhaps we will try it sometime
later.
># Position: 9
># Move: W
>
>r....r.k Weinstein - Elyoseph, Israel 1992
>....bppb This one is really beautiful and should resist computers
>..n.p..p for quite a long time, maybe until next century?
>p.n.P... 1.Ng5!! hxg5 2.hxg5! Rac8 3.Nf6!! Nb8 (black can also
>.p.p.BNP try 3...gxf6, which loses if white play precisely : 4.gxf6
>...P.NP. 4...Rfe8 (best defense) 5.Qh5 Rg8 6.Rxc5! Bg6! 7.Qh4 Bxc5
>qP..QPB. 8.Be4 Ne7 9Kg2 Qd5 10.Bxd5+-)
>..RR..K. 4.Qh5 Bxf6 5.gxf6 gxf6 6.Rxc5 Rxc5 7.Be4 f5 8.Kg2 Rg8 9.Rh1
> 9...Rg7 10.Bh6 Nd7 11.Bxg7+ Kxg7 12.Qxh7+ 1-0
>In fact, Pierre is not sure this one is 100% correct. Any improvements
>are wellcome!
It is not clear to us either whether 1. Ng5!? actually works.