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Subject: Re: Features: Return vs. Effort (new revised table)

Author: Tony Werten

Date: 23:26:30 07/06/04

Go up one level in this thread


On July 06, 2004 at 14:41:45, Stuart Cracraft wrote:

>On July 06, 2004 at 14:16:37, Robert Hyatt wrote:
>
>>On July 06, 2004 at 14:09:39, Stuart Cracraft wrote:
>>
>>>Okay here's a new table with revisions based
>>>on input. Now, higher effort and return numbers
>>>mean more effort and return. And gone is the
>>>value number replaced with Russell's return/effort
>>>ratio. Have revised some numbers to try to fit in
>>>with some opinions.
>>>
>>>The higher the third column the more that feature
>>>gives in program performance for less work expended.
>>>
>>>EFFORT   RETURN    RETURN/EFFORT     Feature
>>>1          5         5               capture ordering
>>>3          4         1.33            null move
>>>4          4         1               null move with verification
>>>4          4         1               search pv first
>>>4          5         1.25            static exchange evaluator
>>
>>This can make a big difference.  IE once you have a SEE procedure working, you
>>can use it to reduce the size of the q-search by over 50%, doubling your search
>>speed instantly.  At very low risk.
>>
>>
>>
>>>4          5         1.25            transposition table
>>>4          5         1.25            transposition table with 2-tier replacement
>>>3          3         1               history heuristic, killers, other ordering
>>>2          1         .5              aspiration
>>>2          2         1               iterative deepening
>>>2          2         1               pawn hashing w/ complex pawn evaluation
>>>3          2         .66             capture extension
>>>1          5         5               check extension
>>>1          1         1               pawn to 6th/7th extension
>>>3          3         1               futility
>>>3          2         .66             razoring
>>>5          3         .6              mate-at-a-glance
>
>To reflect this, I've upped return values. They can go higher
>than 5 now and SEE gets a 6. A few more revisions elsewhere as
>well.
>
>EFFORT   RETURN    RETURN/EFFORT    Feature
>1          10        10              capture ordering
>3          4         1.33            null move
>4          4         1               null move with verification
>4          4         1               search pv first
>2          1         .5              fractional extensions
>4          6         1.5             static exchange evaluator
>4          5         1.25            transposition table
>4          5         1.25            transposition table with 2-tier repl.
>3          3         1               history heuristic, killers, other ordering
>2          1         .5              aspiration

You might want to put this one to 0 :)

Of coarse it depends on the engine, but it seems a very widespread
misunderstanding that aspiration always helps.


>4          5         1.25            book learning
>3          3         1               position learning
>2          2         1               iterative deepening

Way higher return.

>3          1         .33             internal iterative deepening
>2          2         1               pawn hashing w/ complex pawn evaluation
>3          3         1               king+pawn hashing w/ king safety evaluation
>3          2         .66             capture extension
>1          5         5               check extension
>1          1         1               pawn to 6th/7th extension
>3          3         1               futility
>3          2         .66             razoring
>5          3         .6              mate-at-a-glance

From my experience, the effort is higher, since it's a very dangerous piece of
code. Specially since other wrong scoring seems to get damped by alpha beta, but
a wrong score by a maag is deadly.

Tony

>
>Stuart



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