Author: Tijs van Dam
Date: 08:38:48 02/01/00
Go up one level in this thread
On February 01, 2000 at 09:30:05, Robert Hyatt wrote: >> >>I use hash at root for my program GKJunior. But I won't let the root search >>fail high or low on the hash, just use an exact value with its "best move" or >>use a move with not enough draft to search first. This way, a best move will >>always be found at ply=1. I have no problems and the code is not messy. > >you just mentioned one messy detail. "no fail high or low". This means that >for _every_ hash probe, you must be checking to see if you are at ply=1 before >you do the fail high or fail low? All for no benefit at all. > No, like Crafty I use a different funtion for the root search. > > >> >>An advantage is that the search will continue very fast when the opponent makes >>the same move as i was pondering, or to start pondering after making a move. >>There is almost no delay, while crafty seems to take a few seconds to get to the >>same PV as it had before the move was made. >> > > >I do this differently. If I complete a 12 ply search, and start to ponder, >I ponder the 2nd move in the PV, I shift the PV two moves left to get rid of >the move I made and the move i am pondering. I then start the search at old >depth-1 since I already have the PV from old depth-2 done... > I see, I hadn't thought of that. But then this has the same result as storing and probing at root, because depth 1...depth-2 are found immediately. This makes it easier to implement pondering / using the ponder result, because every search can start at depth 1 without cost.
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