Author: Frank Quisinsky
Date: 06:43:55 03/28/04
Go up one level in this thread
On March 28, 2004 at 05:14:07, Uri Blass wrote: >On March 27, 2004 at 22:38:40, Odd Gunnar Malin wrote: > >>On March 27, 2004 at 21:13:53, Peter Berger wrote: >> >>>On March 27, 2004 at 21:07:11, Odd Gunnar Malin wrote: >>> >>>>On March 27, 2004 at 19:51:33, Peter Berger wrote: >>>> >>>>>For about a month I have waited for someone to bring this up now. Occasionally I >>>>>thought I should post about it, but then I thought someone else (a much more >>>>>knowledgeable guy at best) would do it anyway sooner or later. I decided to just >>>>>do it now and not bother to do it very well at all. >>>>> >>>>>This is about Ruffian 2.1.0 I bought at Lokasoft's ( it probably applies to >>>>>other Ruffian 2 versions too). >>>>> >>>>>Now how does Ruffian 2 ponder? >>>>> >>>>>Usually programs assume the second move of the PV as being played, and then >>>>>think as if it were their own move in the meantime. If the expected move gets >>>>>played indeed, some (loads of at times ) time has been saved - else the time is >>>>>lost (despite some potentially useful entries in the hashtable). >>>>> >>>>>Another approach ( inferior) is to just think as if you were the opponent during >>>>>ponder and rely on savings from the hashtable you achieved -you get some useful >>>>>entries in the hashtable anyway, but this can't be an optimal strategy IMHO. >>>>> >>>>>Now Ruffian _does_ think as if it were the opponent during pondering, too, but >>>>>in case the expected move is played it does the same as the usual strategy does >>>>>during pondering but one ply further. The second move in the PV is the move to >>>>>be played in case time has already run out, else some time has been saved of >>>>>course. Again, if another move has been played, the time is lost. >>>>> >>>> >>>>If the engine is running as wb engine there is two methods to show the pv-line: >>>> >>>>1. Send a hint-move for your opponent move and then send the pv in normal way >>>>eg. starting with your next move. >>>>2. Put the hintmove in front of the pv for each time you send the pv. >>>> >>>>You are sure it isn't this second method you observe, eg. do it ever change the >>>>first move in the pv. >>>> >>> >>>Feeling more positive now as I at least thought about this obvious explanation >>>:). >> >>Still a bit strange since if it runs as uci there isn't an otion to show a pv >>like you describe so it will/should be quiet if it don't use the ponder move. >>And running as WB CP have problem showing a pv that start with the players move >>so I guess you look at the pv in the log-window. >> >>>Yes, it will change the first move; else I would obviously make no sense at >>>all. >> >>Well playing the second move from a pv-line doesn't make sense neither, maybe it >>does some advanced pondering with switching pondermove if current pondermove >>lower the score for the player too much eg. is a bad move. >> >>Odd Gunnar > >I assume based on reports that I read Ruffian performs worse with pondering on >that it does something wrong so I will be surprised if it does something that >make sense instead of what peter describes. > >Uri Hi Uri, I reported Per-Ola the bug after my long time match vs. Shredder and wrote here about my opinion. But it seems its more a bug in combination with delete HASH in combination with ponder. Best Frank
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