Author: Albert Silver
Date: 06:46:26 10/20/04
Go up one level in this thread
On October 20, 2004 at 07:15:44, Ed Schröder wrote:
>On October 20, 2004 at 04:51:42, Dom Leste wrote:
>
>>Thank you for replying to my last question, i forgot theses settings also.
>
>>What differences in number does Selective search have?
>
>If you lower the default value (100) it will ensure a more safe search with less
>holes, its disadvantage is that the search becomes slower. The opposite will
>happen with values above 100, the search becomes faster, the risk of holes
>(missing essential moves) becomes bigger.
>
>Reasonable values are in the range of 60-200. Best setting is 100 (default).
>
>
>>Is their a command for good/bad knights & bishops?
>
>Actually there are two tuning possibilities.
>
>[Bad Bishop = 100] * default is 100
>[Pruning = MISC_59] * double eval when in the endgame.
>
>Both are totally untested, hence its undocumented status.
Would it be possible to know the other undocumented parameters and possibly a
minor description and evaluation such as has been done with some in the Pro Deo
parameters pages? I ask because I now have a *very* good idea as to the
difficulty of testing so many things, such as parameters that work well alone or
with another, but combined with yet a 3rd and/or 4th, suddenly are worse, etc.
Not to mention the colossal difficulty in going through them, testing them, and
the huge number of combinations. At least this way, we could break our heads
experimenting with a few.
For example, I have had some luck with some of them:
[Lazyeval MIDG = moderate] * has genuinely helped as far as I can tell
[Pruning = MISC_07]
[Pruning = MISC_17]
[Pawn Pressure MIDG etc.]
and especially
[Pruning = MISC_26] * Endgame extensions
[Pruning = MISC_44] * New endgame extension
no big changes one way or the other with some others such as
[Pruning = MISC_22] * Slightly safer Selectivity
and to a lesser degree
[Pruning = MISC_21] * Lazy Eval (tuning)
which combined with others seems to make a difference.
I've also rejected [MISC_58] despite good results as strange as that may seem. I
just don't like the evaluation oddities it causes, and it makes me very
uncomfortable, even though it seems to really improve the tactics in many
things, and probably other moves as well.
And I've tested and rejected
[MISC_09]
[MISC_10]
[MISC_46]
[MISC_39] I use [MISC_03] but can't get this one to work for me with my
other parameters.
and more especially the new style [King_Safety]. Oddly enough, it seems to make
the King Safety concept weaker. For example, take one of the positions from the
WM Test:
[D]r1b1rk2/2qp1pp1/2p2n1p/p3pP2/1bB1P3/2N3R1/PPPBQ1PP/R6K w - - 0 1
With the old style King Safety, we see Bxh6 as one of the candidates, which is
quite understandable. The correct move is Qe3 of course. If I put the new style,
it completely ignores the kingside, per the mainlines it displays. Even if I
jack up the value to over 170, so I don't use it.
Finally, I appreciate the problem with the [Attacking] parameter and why you
stated it weakens the engine at higher values.
Albert
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.