infinite score & tt

[hgm]

Sorry, a 'not' somehow dropped out of the text. I meant to say they should not go beyond that, in the process of enlarging the aspiration window.

In Fairy-Max I don't do aspiration, but there is pre-correction of the window for the delayed-loss bonus, which has to shift alpha and beta down 1 point in the score range where the bonus would add one point. This can cause alpha to drop below -INF. Fairy-Max uses fail-soft, though, so this is never returned as a score. Instead it would return the value of bestScore kept independently from alpha, which starts at -INF.

The drop of {alpha, beta} below -INF actually describes a real effect, causing a cutoff by this initial value of bestScore. It basicallly says "even if you would be checkmated in this position (score -INF), it would not be good enough for the opponent to go here (because he has apparently already proved a faster mate exists). So don't bother to figure out if you are checkmated here".