Computer Chess Club Archives




Subject: Re: Question for the MTD(f) experts

Author: Dann Corbit

Date: 10:47:06 04/14/04

Go up one level in this thread

On April 14, 2004 at 13:33:38, Robert Hyatt wrote:

>On April 14, 2004 at 03:30:22, Dann Corbit wrote:
>>I decided to toss an MTD(f) search into TSCP, and I've got something wrong, but
>>I can't quite see what it is.
>There is a lot more to do.
>1.  you need to modify the hash table to store 2 bounds, not 1.

That was not done yet.

>2.  the search must be fail-soft.  TSCP isn't.

I had already done that.

>3.  PV has to be yanked from the hash table and that makes it flakey at times as
>has been discussed many times.  There is another way to get the PV, but it is a
>special case solution only for mtd...

Tord showed a very nice way to do that with a clever "hash only" update.

>4.  the convergence has to be accelerated.  IE on a fail high searching v and
>v+1 won't cut it.
>IE this is not a "drop in and go" it is a "rewrite and test" thing to do. :)

Yes.  I am convinced that a program should be either an MTD(f) engine or a PVS
engine but it is a mistake to try to make it become both on demand.

I wrote an MTD(f) driver before but it was just "monkey see - monkey do" in that
I looked at a sample and followed what he did.  Now I am trying to understand
what all of it means and so I thought I would start with something very simple.
This exercise has shown me some things I did not properly understand about

This page took 0.01 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.