Author: Jeremiah Penery
Date: 13:55:32 10/13/02
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On October 13, 2002 at 15:55:05, Vincent Diepeveen wrote: >On October 13, 2002 at 15:47:43, Jeremiah Penery wrote: > >>On October 13, 2002 at 14:14:13, Vincent Diepeveen wrote: >> >>>On October 13, 2002 at 13:50:24, Jeremiah Penery wrote: >>> >>>for any chessprogrammer it is very clear Jeremiah. >>> >>>It's 12 ply and the 6 only means that the hardware search can >>>be up to 6 ply within that 12 ply nominal. >> >>For the millionth time, explain 4(5) then. > >it's a lot easier when you try to imagine how you would start >a search. Look at 4 ply you want to involve other cpu's too. > >You have 480 chess chips. 9 out of 10 is idling anyway >(we know this because everyone says it was capable in theory >to get a billion nodes a second in theory, yet it got only >126 million nodes on average; there is no discussion here) > >you want to use as many cpu's as possible. So at the root you >ask a few chips. Of course you must take into account extensions too. If they needed an exact score from the chess processors, they could do the same search on many processors at once with different bounds, because the hardware searched with a null-window. So it's like MTD researching to converge on the real value, with the potential to take only the amount of time of a single research, also having the side effect of using lots of processors, if that's what your goal is. >If a 4 ply search for this chip is too much, then you split it. and >split it. Giving a 2 ply search to chip A, and a 3 ply search to >chip B. If you want a 4-ply search, how do you get it from a 2-ply plus a 3-ply search on different processors? >The 5 in short has no meaning here. No, it means the hardware search (not counting quiescense or extensions) could be up to 5 ply. :) What it means in relation to the first number, however, is not so clear. But you said above about 12(6), "It's 12 ply and the 6 only means that the hardware search can be up to 6 ply ***within that 12 ply nominal.***" If 5 has no meaning in 4(5), then your previous statement was simply wrong. Else, the meaning of 4 is still not completely clear. >You can see that the mainlines at the start of the game (so before >hashtables are filled with a lot of info that extends lines) >that the lines it gives at 4 , 5 , 6 ply is usually 1 ply long. There is hardly ever a 1-ply line given. After a wrong pondering guess, I often see depth of 3(4), and the mainline is almost always 3-5 ply given, sometimes much longer. Sometimes after a wrong pondering, the first depth given is more like 8(4), with line of about 8 ply. 5(5) is also a common number, and sometimes the lines are 1 ply, but more often 3 or more. If you want, I can go through all the logs later today and make a table of the first search output after a wrong pondering, with the depth - x(x) - and the length of the given PV.
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