Equalizer Iccf

[Michael_R]

First, I have to thank the incredible work of the Stockfish programmers for bringing this engine to a truly high level.
Reading criticisms of the new versions in solving chess tests, I wanted to create a personal variant in this direction, starting from Stockfish dev. 240307, calling it Equalizer 24.4
For now I have ONLY changed the following structure:

// ---------------------------------------------------------------------------------
Value Eval::evaluate(const Position& pos, int optimism) {

assert(!pos.checkers());

int v;
int nnueComplexity;
Value nnue;
int simpleEval = simple_eval(pos, pos.side_to_move());
int abs_simpleEval = std::abs(simpleEval);

if (abs_simpleEval > 3000)
{
...
}
else if (abs_simpleEval > 2500)
{
...
}
else if (abs_simpleEval > 2000)
{
...
}
else if (abs_simpleEval > 1500)
{
...
}
else if (abs_simpleEval > 1000)
{
...
}
else if (abs_simpleEval > 500)
{
...
}
else
{
...
}

// Guarantee evaluation does not hit the tablebase range
v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
return v;
}
// ---------------------------------------------------------------------------------

By optimizing each sector, the resolution of chess tests is incredibly improved, significantly improved in fast times, less so in slow ones.

tc=1.0+0.01
Score of Equalizer_24.4 vs Stockfish_240307: 5307 - 4673 - 10020 [515.85] 20000
tc=10.0+0.1
Score of Equalizer_24.4 vs Stockfish_240307: 144 - 77 - 1779 [516.75] 2000

These days I started using it on PlayChess.
I want to point out that I have no credit for this engine, all credit should be given to the Stockfish programmers, I'm just equalizing the evaluate() module.

[Master Om]

can u share the exe please?

[Michael_R]

I'm sorry, but for now I have no intention of distributing it, it's just for personal experimentation.
However, I inserted the modified part, anyone can customize it.