Tsumego solver

Picture

Across 19 Down 19 Kind

Board edge at: top left right bottom

To play Attacker

Engine settings

Net Visits force CPU always count ko threats

KataGo runs in your browser. The rest of the board is filled in so only the problem matters (a "tsumego frame", idea from LizGoban). When one colour surrounds the problem (corners, edges) that colour gets everything outside. When both colours face out (centre problems), each side outside goes to the colour of the nearest stones, and what's at stake is found by reading the problem once with each side to move (marked on the stones). Each side gets virtual ko threats: kills/lives works even when the opponent has plenty of them; a ko shows how many more threats than the opponent you'd need (an N-step ko where you have to find the first threat needs N). Percentages: win chance when the opponent / you have plenty of threats. Stones in board photos are found by moku-v4 (AGPL-3.0, from the Kaya project).