Author: Stefan Meyer-Kahlen
Date: 11:41:53 04/17/04
Go up one level in this thread
On April 17, 2004 at 02:58:10, Andrey Popov wrote: >I have two questions: > >>* The engine should boot and wait for input from the GUI, >> the engine should wait for the "isready" or "setoption" command to set up its >> internal parameters as the boot process should be as quick as possible. >> >When should an engine verify the presence of all its parts (dlls etc.) >and tell to GUI an error message if something is absent? > >>* multipv <num> >>this for the multi pv mode. >>for the best move/pv add "multipv 1" in the string when you send the pv. >>in k-best mode always send all k variants in k strings together. >> >As far as I understood, the engine must silently accumulate >the information (pv,score etc.) about all moves. >At the end of each ply the engine must sort all these moves by score >and send to the GUI something like the following: >info multipv 1 depth 2 score 25 time 100 nodes 33000 nps 33 pv e2e4 e7e5 >info multipv 2 depth 2 score 23 time 100 nodes 33000 nps 33 pv d2d4 g8f6 >info multipv 3 depth 2 score 22 time 100 nodes 33000 nps 33 pv c2c4 c7c5 >All "time","nodes" and "nps" must from the end of the ply. >Therefore, they must be equal for all moves. Am I right? No, they are different. If you search a move and find out, that it is one of the k best, you just send the lines of your k best moves so far. Example: At depth 4 you have searched e3 and d3 and those are your two best moves, so you send: info multipv 1 depth 4 seldepth 7 time 29 score cp 6 nodes 1120 pv e2e3 g8f6 info multipv 2 depth 4 seldepth 7 time 31 score cp 5 nodes 773 pv d2d3 b8c6 Now you start with depth 5. After searching e3 there, you display the lines of your two best moves so far. info multipv 1 depth 5 seldepth 9 time 129 score cp 8 nodes 13420 pv e2e3 e7e6 info multipv 2 depth 4 seldepth 7 time 31 score cp 5 nodes 773 pv d2d3 b8c6 If e3 gets a fail low it is still your best move at this ply as you haven't searched any other move there. So the display above changes to info multipv 1 depth 5 seldepth 9 time 129 score cp -99 nodes 13420 pv e2e3 e7e6 info multipv 2 depth 4 seldepth 7 time 31 score cp 5 nodes 773 pv d2d3 b8c6 Stefan
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.