Author: Ed Schröder
Date: 22:13:50 09/25/99
Go up one level in this thread
On September 25, 1999 at 18:44:17, Peter McKenzie wrote:
>In a game on ICC Beadle (LambChop) reached the following interesting position:
>
>2kr1b1r/ppp4p/1q4p1/3p1p1b/3N4/2PQPPP1/PP1N2P1/R4RK1 w - - 0 17
>
>Tactics:
>
>Here LambChop blundered with Nxf5, it needs an 8 ply search to avoid Nxf5. The
>key variation being Nxf5 gxf5 Qxf5+ Kb8 Qxh5 Qxe3+ Rf2 Bc5 Rf1 Qxd2. This is a
>10 ply variation, but we have a couple of checks in there so the check extension
>sallows it to be seen in 8 ply.
>
>My q-srch prunes out captures that look bad, so Qxd2 is pruned as the simple
>algorithm I use thinks d2 is protected by the R on f2 :-( I guess if my pruning
>algorithm in q-srch was smarter then I'd see this line one ply earlier. I'd
>also see it earlier if I just looked at all captures in q-srch...
>
>How many ply do other programs need to avoid Nxf5 ? I know that crafty needs 8
>ply too...
>
>
>Positional:
>
>I was slightly surprised when Bob Hyatt said he thought white was doing badly
>anyway (crafty agreed). I personally think that white is doing fine, I actually
>prefer white's position.
>
>Here is how I see the position:
>White has 2 knights vs two bishops, so white should try to keep the position
>somewhat closed. Currently the knights are quite well posted, while the Bh5 is
>quite bad although the Bf8 is potentially very good but currently not doing
>much.
>
>White's pawn structure is weakened, but black isn't currently in a position to
>take advantage of this. White will probably play f4 eventually, leaving holes
>on e4 and g4 but this doesn't look too bad for white as black doesn't have a
>knight to sink in there. Also, the white knights cover those squares quite
>well, and after f4 the Bh5 is really locked out.
>
>White has a clear and simple plan of advancing on the queenside. I think black
>should try to open the position and infiltrate the dark squares, but its not
>clear to me how to achieve this.
>
>I think white should play 1.b4 which is in harmony with the plan of advancing on
>the queenside, it also dissuades c5 (thereby keeping the strong knight on d4)
>and has the added bonus of possibly threatening Nxf5. I wouldn't worry about
>Nxf5 too much though, as even if it wins a pawn the variations look very open
>and dangerous for white.
>
>After 1.b4, ...c5 looks poor. Simply 2.bxc5 followed by 3.Rab1 with good
>initiative for white.
>
>Another line is 1.b4 Bd6 2.f4 Rhe8 3.a4 threatening a5 Qa6 b5 trapping the black
>queen :-)
>
>Maybe something like Qf6 is best for black? The idea being to play g5
>eventually. Pretty slow though.
>
>So there you have it, the opinion of someone used to be 2300 Fide but these days
>struggles to maintain a 2000 ICC bullet rating :-)
:-)
Here is what Rebel makes of it, it fails low at 7 plies score -2.xx and
then switches to a4 and later to b4. Below is the log.
Ed
------------------------------------------------
Thinking....
+---+---+---+---+---+---+---+---+ am Nxf5 - NXF5.EPD
8 | | | *K| *R| | *B| | *R|
+---+---+---+---+---+---+---+---+ 00:00:00 00:00:00
7 | *p| *p| *p| | | | | *p|
+---+---+---+---+---+---+---+---+
6 | | *Q| | | | | *p| | Time infinite
+---+---+---+---+---+---+---+---+ Hash 60 Mb
5 | | | | *p| | *p| | *B| Engine Rebel Century
+---+---+---+---+---+---+---+---+ Personality Rebel Century
4 | | | | N | | | | | anti-GM Off
+---+---+---+---+---+---+---+---+ System Tiger Off
3 | | | p | Q | p | p | p | | Combination Off
+---+---+---+---+---+---+---+---+ Style Normal
2 | p | p | | N | | | p | | Strength Strongest
+---+---+---+---+---+---+---+---+ Search Normal Search
1 | R | | | | | R | K | |
+---+---+---+---+---+---+---+---+
a b c d e f g h
2kr1b1r/ppp4p/1q4p1/3p1p1b/3N4/2PQPPP1/PP1N2P1/R4RK1 w - -
[Event "?"]
[Site "? "]
[Date "1999.09.26"]
[Round "?"]
[White "am Nxf5"]
[Black "NXF5.EPD"]
[Result "*"]
[WhiteElo "?"]
[BlackElo "?"]
[FEN "2kr1b1r/ppp4p/1q4p1/3p1p1b/3N4/2PQPPP1/PP1N2P1/R4RK1 w - - 0 1"]
1.*
00:00:00 1.00 -3.54 1.Ne6 Qxe6
00:00:00 1.01 -0.36 1.Nxf5 Qxb2
00:00:00 2.00 -0.09 1.Nxf5 Qxb2 2.Rfb1 Qa3 3.Nb3
00:00:00 3.00 -0.09 1.Nxf5 Qxb2 2.Rfb1 Qa3 3.Nb3
00:00:00 4.00 -0.09 1.Nxf5 Qxb2 2.Rfb1 Qa3 3.Nb3
00:00:00 5.00 -0.11 1.Nxf5 Bxf3 2.Rxf3 gxf5 3.Nb3 Bg7
4.Qxf5+ Kb8 (0)
00:00:01 6.00 -0.17 1.Nxf5 Qxb2 2.Rab1 Qa3 3.g4 Bxg4
4.fxg4 gxf5 5.Qxf5+ Kb8 (1)
00:00:04 7.00 -2.64 1.Nxf5 gxf5 2.g4 Be8 3.Qxf5+ Rd7
4.Rae1 Qxb2 (3)
00:00:11 7.01 -0.48 1.a4 Bh6 2.Rae1 Rhf8 3.b4 Qd6 4.Ne2
00:00:28 8.00 -0.50 1.a4 Bh6 2.Rae1 Rhf8 3.b4 Qd6 4.Kh2
Rfe8 (23)
00:00:35 8.03 -0.47 1.b4 Bd6 2.Kh2 Rhf8 3.a4 Be5 4.a5
Qd6 5.f4 Bg7 (29)
>LambChop gives white as +0.4 after 9ply, and wants to play a4.
>
>So what do other people/programs think?
>cheers,
>Peter
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