Author: Stuart Cracraft
Date: 21:05:59 03/06/06
Go up one level in this thread
On March 06, 2006 at 23:59:59, Dann Corbit wrote: >On March 06, 2006 at 23:55:17, Dann Corbit wrote: > >>On March 06, 2006 at 23:39:36, Stuart Cracraft wrote: >> >>>On March 06, 2006 at 22:47:18, Dann Corbit wrote: >>> >>>>On March 06, 2006 at 22:13:56, Stuart Cracraft wrote: >>>>[snip] >>>>>Discouraging Dan. Discouraging. >>>> >>>>Suppose that you are 3 lines away from approximately the same result. >>>> >>>>BTW, I have had a crafty version score 300/300 with the same time controls. >>>> >>>>The only difficult problem in this set is WAC.230. >>>> >>>>I think that WAC is a great set to start working with on a chess engine. >>>>After a few months you are going to graduate to something tougher. >>>> >>>>I guess that there is some simple bug that is costing you 80% or more of the >>>>misses. >>>> >>>>It sounds like an advanced engine from the things I have read so far. >>>> >>>>I think I saw a list of the missed problems by your program. I guess that I may >>>>see a theme problem when I go over them. >>> >>>Thanks - I look forward to those comments at your availability. >>> >>>I reran the whole 300 suite at 10 seconds each this evening, >>>due to Bob's comment, and pulled the failed 29 (Bob failed 9 >>>I believe.) >>> >>>Then I reran against just my 29 and found that only 24 failed the >>>second time, at the same time control. >>> >>>This tells me that there is something about the test that is not >>>reproducible, based on either the ordering of the tests in the suite >>>or aspects being carried from test position to test position (hash >>>tables, history heuristic, etc.) I am not sure what it is. >>> >>>To test this theory, I took the 29 that failed of which only 24 failed >>>the second time and reversed them so that the last came first and retested. >>>This time 4 of the 29 were solved instead of 5. This difference of one is >>>too small to claim an ordering result for just 29 position sample size. >>> >>>Still this indicates that instead of failing 29 I am failing 24-25 >>>and I am not sure what would cause it. Before every iterative deepening >>>ply 1 search, I clear out the history heuristic table, the hash tables, >>>and the principal variation arrays. >>> >>>Still that is only 4-5 more leaving 24-25 left, arguably 15-16 if one >>>wants to aspire as high as Crafty. >>> >>>I am at a total roadblock on the subject. As I mentioned, I will be >>>putting money where my mouth is and making a signficant donation to >>>the board sponsors for guidance to a solution of gaining say another >>>10 right above my current 271 at 10 seconds. (Hopefully that's legal >>>here.) >> >>This sounds like a bug. >>If you analyze a new position, you should definitely clear the hash table >>between analysis runs. > >Note: >A good way to know you should clear the hash is if the node you are given to >analyze is not a pv node in the hash table. > >If the node is a PV node in the hash table, then don't bother to clear it. > This last note went right over my head. I have a routine, called iterate(), which does an iterative deepning PVS search using a for loop. Prior to the for loop it clears the hash table, the history heuristic table and the pv tables to prevent interference between moves on test suites. I should probably make it not clear the hash table, or maybe even the history heuristic table or pv if a regular game is being played, but no testing has been done for that comparison so I just clear everything. Maybe you are talking about something else than the above. When/where would I clear the hash? I take the pv of the last iteration and stuff it into the hash table to ensure it is there so that the pv can make the PVS search function properly. When entering a search, I am currently generating all moves, putting the hash and any pv move at the top, sorting based on see, mvv/lva, and basic pc/sq, and then searching the top in the list (all attempts to avoid the genmoves and search the hash move only have not been successful and all results have always been better for me doing a full move gen.)
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