static null move pruning margin

[xr_a_y]

Have you ever consider using a negative (little !) margin for static null move pruning at depth 1 ?

We often seek for parameters in a formula like this one

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if ( staticScore > beta + depth * slope + offset ) return staticScore

And often "offset" is 0 and is omitted and coeff is something around 100cp.

I am wondering if (and testing this currently) using offset around -100 or -150 and tune slope might be good, even such that slope + offset is a little negative.

[hgm]

This is just redefining d=1 as a QS level, right? So it will not hurt, but just lead to a funny redefinition of 'depth', exaggerating all depths by 1, and otherwise doing the same search.

[Koivisto]

we have this in Koivisto search

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if (depth == 1 && staticEval > beta && ownThreats && !enemyThreats)
            return beta;

Threats are defined as smaller piece attacking larger.

[hgm]

So what are 'threats'?

[Koivisto]

So what are 'threats'?

Threats are defined as a smaller piece attacking a larger piece. Pawn attacking knight for example.