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# Ponder ON or OFF ?

QueensideCastler wrote:
intx13 wrote:
A simpler way to think about it might be to consider the engine's "strength" as a percentage of its maximum strength. Without pondering, each engine plays at 100% strength. With pondering, each engine plays at 100% strength during its turn and 25% strength during the other player's turn (assuming 25% accuracy in pondering guesses), but each turn is half as long (because only half the CPU time is available). So with pondering, the overall engine strength is only 62.5% of its maximum.

How about this scenario - my CPU is 5960X (8 physical cores) if i enable ponder 4 will be asigned to each engine. From my engine testing the predicted move ratio is much higher than 25% it is actually in the 50-60% range, most often 58-63% so lets make it 60%. Can you calculate the difference in performance between 4-core ponder and 100% CPU resource.

Assuming same engine, fixed time per turn, each engine able to use all cores at 100% if available, 0.5*100% + 0.5*60% = 80% –  intx13 16 hours ago

In general you can estimate the new strength as 50% + 1/2 * (predicted move accuracy). But this becomes less relevant the more you move away from the theoretical scenario I described in my other answer. If you were running two different engines with no per-move time restriction and those engines might not use all cores to 100% during normal operation, this estimate is meaningless.

It looks like with 60% ponder accuracy it comes with an 20% penalty in overall playing strength, if shared cores

My 5960X is no exception

http://chess.stackexchange.com/questions/9336/permanent-brain

The Proof of the Pudding as they Say :) is...do both Engines with Ponder ON or OFF Search as Deep and as effective ?

From what I can See of it with Ponder ON and the Advantage of Guessing 60%+ of the Opponents moves the Engines Search just as Deep and as effective

W.C.N
If the overall playing strength is 80% with 60% ponder accuracy, would't the increased time as result of pondering outweights the -20% penalty? –  Nordlandia Jun 27 at 14:50

If the two engines share CPU resources, then you never really get increased time. Half your time is spent handicapped to half the CPU, and the other half is spent handicapped to half the CPU and the penalty for having to guess at the opponent's move. You'll never do as well as having the entire CPU (and no guessing penalty) for half the length of time. –  intx13 Jun 28 at 20:48

If you could guess opponent's moves with 100% accuracy then pondering would be the same as just splitting CPU time. But anything less than 100% you are performing worse. – intx13 Jun 28 at 20:51
QueensideCastler wrote:
If the overall playing strength is 80% with 60% ponder accuracy, would't the increased time as result of pondering outweights the -20% penalty? –  Nordlandia Jun 27 at 14:50

If the two engines share CPU resources, then you never really get increased time. Half your time is spent handicapped to half the CPU, and the other half is spent handicapped to half the CPU and the penalty for having to guess at the opponent's move. You'll never do as well as having the entire CPU (and no guessing penalty) for half the length of time. –  intx13 Jun 28 at 20:48

If you could guess opponent's moves with 100% accuracy then pondering would be the same as just splitting CPU time. But anything less than 100% you are performing worse. – intx13 Jun 28 at 20:51

Have you actually Checked (Ponder ON/OFF) Regarding how Deep and effective Both types are ?

The Logic ? says this and that but the Engines Still find the same moves...other than if they Guess Correct or not!

I would put My Money on a 6/4 Guess Ratio being better than a 5/5 Ratio or less

W.C.N
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