Author: José Carlos
Date: 01:07:53 08/06/04
Go up one level in this thread
On August 05, 2004 at 22:26:54, Uri Blass wrote: >On August 05, 2004 at 20:54:15, José Carlos wrote: > >>On August 05, 2004 at 20:01:29, Cesar Contreras wrote: >> >>>I'm trying to improve my move ordering, with a little success, principal due to >>>correct my understanding and implementation MVA\LVV. I had not sucess with SEE. >>>Anyway, i think my tree it's still too big. >>> >>>I need to know if i can do any more about it. >>> >>>currently i do: >>> >>>1.- Moves on transposition, ordered by evaluation (some one suggested me order >>>by node count, why do you think?) >> >> I guess he meant _at the root_. In the root position of the search, you want >>to try the PV move first (because your best move so far) and then all the rest, >>which you expect to quickly fail low. As the world isn't perfect, you'll fail >>high on a non pv move sometimes. Due to alphabeta nature, you want that to >>happen as soon as possible. Node count is a good general idea, because more >>nodes means "in the last iteration, it was harder to refute (fail low) this >>move, so it might be good". >> I use node count, but I've found better (for my program) to try previous pv >>moves before. For example, in the initial position, e4 is your pv move until >>iteration 7. Then you fail high on d4. At iteration 10 you fail high on Nf3. In >>this case, for iteration 11, I first search Nf3, second I search d4, then e4, >>and after that, all the other moves, sorted by node count. > >This is exactly killer moves and it can be improvement only for programs that do >not use killer moves in the first ply. > >It was the case for old movei when I did not think about the first ply when I >defined killer moves but I corrected it later. > >Uri In my case, I don't use killer moves at the root. Any number of fail highs are all recorded (not a fixed number like killer moves). I have a different function so search the root position, where I do many different things. In particular, the way I sort moves there has changed many times. José C.
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