Author: Robert Hyatt
Date: 08:01:20 11/28/00
Go up one level in this thread
On November 28, 2000 at 07:07:14, Uri Blass wrote: >On November 27, 2000 at 22:10:07, Mogens Larsen wrote: > >>On November 27, 2000 at 21:52:40, Robert Hyatt wrote: >> >>>What I was referring to was playing the right move with a score that is < 0, >>>when the move is a _winning_ move. If the program _knows_ it is winning, it >>>will have a positive score... If it doesn't know this, it is playing it for >>>the wrong reason. >> >>That's just a question of depth since the score is obviously improving. When a >>program is improving its score by chosing the right moves (to a certain extent >>as inaccuracy tends to creep in the further you go in the PV), then I consider >>it to be the right reason. >> >>If Nxh6 had been the only correct move in the PV, but the score > 0, then it's a >>right move for the wrong reason to me. The score will improve if the PV keeps on >>approaching the correct variation. You're doing a TC imitation by staring at the >>score IMHO. >> >>What score would imply "right reason" at depth 11? >> >>Mogens. > >The meaning of depth 11 is not clear so it is impossible to answer. >The interesting question is the number of plies in the main line. > >The meaning of the right reason is also not clear. >Hyatt said it is a positive score but I think that seeing that other moves are >worse is also a good reson to play Nxh6 > >I decided to test Gandalf4.32g at the position 4 plies after the initial >position and I see that Gandalf get the same score(-0.12) at depth 8 after 111 >seconds and 7700 knodes on my pIII450 when the score is not changed at depth >9(It probably decides to stop analyzing Qg4 because analyzing this move is too >hard for it at depth 9). > >It means that 11 in the original position is equal to 8 ot 9 in the position 4 >plies later. > >Gandalf fails high later at depth 10(time 10:40 nodes 44850 and score 0.19 for >white without a main line). > >I guess that if depth 11 in the original position is eqvivalent to depth 8 or 9 >in the position 4 plies later than 10 in the position 4 plies later is >eqvivalent to 12 or 13 in the original position so I guess that gandalf4.32g >needs depth 12 or 13 to find that Nxh6 has positve score. > >I have no idea how to translate depth to plies so I do not do it. > >I guess that the difference in depth between 2 positions is not changed but I >may be wrong. > >Uri That is a hard thing to evaluate. If you move down the PV 4 plies and start searching, and assuming you searched to depth=15 to start with, then starting here with depth=11 is not always equivalent. If the first two moves were checks, they would have extended the search by two additional plies. Stepping past the two checks loses the two extensions. Your 11 ply search might not see what the original 15 ply search saw. I just ignore this. It is good for nothing but headaches. :)
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