Author: Tord Romstad
Date: 09:33:43 05/26/04
Go up one level in this thread
On May 25, 2004 at 22:12:04, Tom Likens wrote: >On May 25, 2004 at 20:45:08, Tord Romstad wrote: > >>2. Write a function to compute a mirror image of the position on the board >> (i.e. black and white sides interchanged). Find a big file of EPD >> positions, and let your engine parse the file and evaluate each position >> and its mirror image. This helps you find asymmetry bugs in the evaluation >> function. This test should be done almost every time you do a change in >> the eval. It is surprising how easy it is to introduce new asymmetry bugs. > >This is a great way to catch asymmetry bugs. Don't forget that you can >mirror the board top-to-bottom *and* left-to-right. If you carry this >out you will get three additional boards to compare against (four if you >count the original position). > >1. original position >2. T-2-B >3. L-2-R >4. T-2-B followed by L-2-R In my case, the evaluation function isn't left-to-right symmetric. For instance, I have a penalty for a knight on c3/c6 blocking the c pawn in the opening, but no corresponding evaluation term for the king's knight. Tord
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.