OpenChess

Hello,

My engine is very hard to tune because of its Sensitivity.
When I change a single value (for example square F3 of PST knight from 5 to 6 or 4), I note a big impact on bahaviour of my engine for certain tactical position.

Is this normal or is this the sign of the existence of a hidden problem ?

Thanks,

One does not tune an engine based on a 'certain tactical position', but by its score in a few thousand games. You should only worry when changing the PST value of Knights on f3 would change the number of wins in, say, 1000 games from 200 to 300. That would suggest there is not eough diversity in the starting positions you use.