Author: Bob Durrett
Date: 17:32:57 12/09/03
Go up one level in this thread
On December 09, 2003 at 11:55:11, Robert Hyatt wrote: >On December 09, 2003 at 11:13:56, martin fierz wrote: > >>On December 09, 2003 at 10:50:23, Sune Fischer wrote: >> >>[snip] >> >>>If the bare engine had been playing he would have had to add a few things the >>>GUI normally takes care of. >>>For UCI engines it is expected that the GUI handles certain (trivial) things. >> >>claiming a draw on 3-fold repetition is *not* a trivial thing. there are >>different possible cases: >> >>1) if your opponent avoids it, he loses >>2) if your opponent avoids it, he wins >> >>in case 2) you should of course claim the draw, because perhaps he will notice >>he could avoid it. in case 1) however, you can safely repeat the moves, and not >>claim the draw. it is *not* mandatory to claim a draw on the 3rd repetition. so >>you should basically not claim it if you might win if your opponent avoids the >>draw. > >This is a zero-sum game. If I avoid a draw, I am doing so because I think I >can win. Therefore my opponent will be trying to draw to avoid the same loss. > >It doesn't matter what my _real_ opponent will choose to do, what matters is >what I _think_ he will do inside my search, because my search is given the >task of playing a move that repeats for the 2nd or 3rd time (with a score of >0.00) or playing a move that avoids the repetition and doesn't give my opponent >the opportunity to repeat. When you repeat for the third time, you definitely >hand a draw to your opponent. He can take it or decline, beyond your control. >But you have put the future of the game in his hands.. I don't repeat hoping >my opponent won't. > >> >>how do you expect a GUI to make the right decision? imagine the following >>absurdity: jonny is running without GUI and happily repeats moves against >>shredder, and does not claim the draw because the engine doesn't know about it. >>shredder has a bug and allows a 3-fold repetition but will deviate before the >>fourth repetition. now shredders GUI stops shredder from moving, and says "i >>claim a draw with my move XY because of 3fold repetition" - this would have been >>hilarious for everybody except SMK :-) > >The GUI doesn't make _any_ decision. It plays the move the engine supplies. In the following I am not talking just about one specific chess-playing machine, but a "generic" or "typical" chess machine. Specific machines may not be typical. [We may not know all the details regarding the internal workings of ALL chess-playing machines.] Rhetorical Question: "What software typically generates the original position evaluation score?" Perhaps the "main engine" returns not only a move [in some specific way] but also additional information [such as, but not limited to, the position evaluation score.] The engine "returns" the information, presumably, to the GUI. Subsequently or concurrently, the GUI "processes" some or all of the information provided to it [perhaps incrementally as it comes in], plus any information generated in the GUI software or elsewhere [such as tablebase software, clocks, stored user preferences, and user real-time inputs]. The GUI then "makes a decision." [Like it or not, the GUI is doing this, not an engine.] Then the GUI "decides" what to display to the human operator. The GUI could be programmed to stop and start the engine(s) under certain circumstances. [A trivial example would be when the GUI receives a "stop" or "start" command from the human user.] In my opinion, ChessBase displays a 0.00 evaluation score sometimes when it should not and visa versa. [I am prepared to discuss that more if someone from Chessbase wants to.] Note that we have said nothing about the "format" or "protocols" associated with the information transfers occuring inside the "chess-playing machine." Clocking, interrupts, registers, and the like are just too hard to talk about. Bob D. >If that leads to a 3-fold repetition, the GUI claims it correctly... I don't >understand this "how do you expect the GUI to make the right decision?" >stuff when the GUI only does what the engine tells it to do. If the engine >says "play this move" then the GUI plays that move, and if that produces a >3-fold (or 50-move-rule) draw, then the GUI claims it, _knowing_ that the >engine knew that was happening... > > > > > > >> >>since 3fold repetition is something you claim or don't claim based on the >>current position, it is clearly something the GUI shouldn't be doing! > >It doesn't. The engine makes the choice to repeat. But once it does, >it _knows_ it wants the draw, else the engine would have avoided it. You >are saying the engine plays a move leading to a forced draw, but it isn't >sure it wants to claim it. That is simply wrong. The search doesn't work >that way... > > > >> >>cheers >> martin
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.