Is there a name for this move ordering idea?

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thevinenator
Posts: 68
Joined: Tue Jun 02, 2015 11:02 pm
Real Name: Vince

Is there a name for this move ordering idea?

Post by thevinenator » Sat Dec 24, 2016 4:18 pm

while watching (yawn) some test searches with my engine, I noticed something interesting. The engine sometimes will oscillate between what it thinks are best moves between plys. Sometimes the moves are the correct moves, sometimes not, but going to the next ply, the program will first play the best move from the last ply (standard stuff). But it did think those other moves from previous plys, which aren't the best choice now, were good at some point, so perhaps they might be good again.

So my idea is to somehow incorporate those previously "plied" moves into the move ordering perhaps after the TT (previous best move), but before using the normal move ordering selection (usually good captures).

The idea is:
1. it actually might be the best move, but it might sort low
2. might be bad for a reason and should cause a cutoff sooner.
3. (other reasons TBD).

has anyone tried this and if so, has it merit, and does it have a name?
"An Engine's strength flows from the Search. But beware, pruning, extensions, reductions; the dark side of the Search are they. Once you start down the dark path, it will dominate and consume you, as it has to so many developers before.” -- Yoda

H.G.Muller
Posts: 190
Joined: Sun Jul 14, 2013 10:00 am
Real Name: H.G. Muller

Re: Is there a name for this move ordering idea?

Post by H.G.Muller » Sun Dec 25, 2016 2:07 pm

Normally, when deepening iteratively (either internally or in the root), one sorts the best move in front for the next iteration. That means that moves that were found to be best in any iteration preceed all moves that never came up as best, in the move list. Some engines even sort all moves in front that beat alpha,without waiting for the end of the iteration.

thevinenator
Posts: 68
Joined: Tue Jun 02, 2015 11:02 pm
Real Name: Vince

Re: Is there a name for this move ordering idea?

Post by thevinenator » Sun Dec 25, 2016 2:58 pm

Ok. I'll take a look at how i'm handling the move list at the root.

thanks for the holiday present! LOL
"An Engine's strength flows from the Search. But beware, pruning, extensions, reductions; the dark side of the Search are they. Once you start down the dark path, it will dominate and consume you, as it has to so many developers before.” -- Yoda

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