Author: Serge Desmarais
Date: 22:34:30 09/28/98
Go up one level in this thread
On September 28, 1998 at 09:28:03, Robert Hyatt wrote: >On September 28, 1998 at 03:27:27, blass uri wrote: > >> >>On September 27, 1998 at 20:07:10, Serge Desmarais wrote: >> >>>On September 21, 1998 at 19:46:15, Amir Ban wrote: >>> >>>>On September 21, 1998 at 18:49:25, José de Jesús García Ruvalcaba wrote: >>>> >>>>>On September 21, 1998 at 16:12:55, Amir Ban wrote: >>>>> >>>>>>On September 21, 1998 at 08:11:22, blass uri wrote: >>>>>> >>>>>>>Is the version for sale better than the 16bit version that I and thorsten have? >>>>>>>(I am not talking about speed because it is obvious that 32bit is faster than >>>>>>>16bit) >>>>>>> >>>>>> >>>>>>You both got a version that was close to the final one but not the final one. >>>>>>There were some changes added, but I don't think they affect playing strength >>>>>>significantly. One change that was in the final 32-bit beta version (that played >>>>>>against Zifroni) was finally not included, and the released version is almost >>>>>>identical to the one that played Yudasin. >>>>>> >>>>>> >>>>>>>Is there an option to let underpromotion(not to queen) in the version for sale? >>>>>>> >>>>>> >>>>>>No. >>>>>> >>>>>>Amir >>>>> >>>>> I am surprised. What does it mean that there is no option in Junior5 to let >>>>>underpromotion? >>>> >>>> >>>>ok, let's be accurate: The interface allows you to underpromote when entering >>>>moves, but Junior does not consider underpromotions in its search. >>>> >>>>Amir >>> >>> >>>That means if the only way to draw in the endgame for Junior, it will lose only >>>for not considering the ONLY legal move that would save the game? >> >>yes >> >>> And what abou >>>the "typical combinations" winning a piece, like QxN+, KxQ, Pmove=N+ and >then NxQ ending up a knight? >> >> >>Junior will not see these combinations but there are not common(The probability >>that it will be relevant in a game is less than 1%) >> >>This "bug" was done in purpose to help Junior to save time in more than 99% of >>the cases when only promotion to queen is logical. >> >>Uri >>> >>>Serge Desmarais > > > >actually it hardly saves anything at all. In 99.9% of pawn promotions, in a >full-width tree search, the promoted piece is "ripped" instantly. Which means >that after you search e8=Q, you *won't* have to search e8=R, because the >position after Rxe8 is the same no matter what was there before, and the hash >table prevents searching the nonsense. And when the promoted piece doesn't get >ripped away instantly, the big material advantage of having a queen means the >under-promotions get pruned away very quickly, *except* for positions where they >do count. Burt Wendroff (previous post of mine) would argue with you about how >frequently it comes up. It doesn't matter *how frequently* it only matters >*if*. > >Because if you don't do it you will draw a won ending, or lose a drawn ending, >or lose a won ending. I don't think it's a worthwhile optimization... > >All it does is make the move generation a little simpler... If you examine Fritz play in such positions, you will notice that when the promoted pawn is threatened of an instant capture, Fritz will almost NEVER promote to a queen, but will make a rook most of the time, as if to make it less attractive for the opponent to capture it? (seems so if we apply a "human reasonning" to this) Unless it "feels" it less costly to "lose" a rook than a queen? I do not have the explanation for that way of playing. Serge Desmarais
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.