Author: Dieter Buerssner
Date: 10:25:19 09/17/02
Go up one level in this thread
On September 16, 2002 at 19:17:08, martin fierz wrote:
>>>>>> 8/8/4K1p1/4PpB1/3p1P1P/5n2/4k3/8 b - -
>3 after all :-) or some form of knowledge that the knight can come to the
>rescue. anyway, it gets a bit complicated :-(
Yes. One can also construct positions with connected passed pawns of rook and
knight pawns, that are drawn. But your condition 3 also seems not fullfilled.
I also try to be careful with such rules (that give really high positional
bonus). I try to think, either the rule should have essentially no exceptions,
or the search will find the exceptions fast.
>i still like the idea of pawn on 7th rank = +3 in positions where the total eval
>is >+7 or so (or +4 with >+8 or whatever). should make you find the 2...Nd4
>line, right?
Yes and no. 2...Nd4 is seen fast in the mainline:
320305 2.476 5.26 9t 1...d3 2. Kf7 Nd4 3. e6 Nxe6 4. Kxe6 d2 5. Kf6
d1=Q 6. Kxg6 Qd5 {571}
But what happens here?
567274 4.610 4.91 10t 1...d3 2. Kf7 d2 3. e6 d1=Q 4. e7 Qd7 5. Bf6
Nxh4 6. Kf8 Qd6 7. Be5H {991}
Well, now the search sees lines like (after 1...d3 2. Kf7 Nd4):
3. Kxg6 d2 4. h5 d1=Q 5. h6 Ne6 6. h7
And again we have the large positional score for the pawn on 7th rank. This is
(disregarding extensions) already 10 ply after the root position. Some more
plies are needed to see, that h7 won't help here. After all, still a rather deep
search is needed, and probably it would still make my engine draw this position.
Instead of +7 or 8 scores, I'd see only +5 scores, but nothing more may change.
Regards,
Dieter
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