Syzygy endgame tablebases

Black is losing with DTZ 150

This is a blessed loss. Mate can be forced, but a draw can be achieved under the fifty-move rule.

KQRRvKQR.pgn lichess.org

Histogram: KQRR winning vs. KQR (log scale)

Longest KQRRvKQR phases

KQRRvKQR statistics (unique positions)

White wins:
229,418,640,157 (67.7%)
Frustrated white wins:
811,468 (0.0%)
Draws:
43,752,515,108 (12.9%)
Frustrated black wins:
395,902 (0.0%)
Black wins:
65,838,168,903 (19.4%)
KQRRvKQR.json (?)