chrilly wrote:
Depending on the exact rules, GHI problems can cause a search to return incorrect results. You could for example mis a win that is within the search horizon, which would have been observed if the same tree was searched without using the transposition table.I have never really understand the point behind GHI. One can reach the same position over 2 different variations/graphs. But what bad playing behaviour is caused by GHI?
Stupid side-Question: What is SuperKo? Is it general repetition of positionIn general superko means that repetition of any position is illegal (in contrast to only 2-ply cycles). There are various flavors of superko rules. The simplest one is positional superko, which only looks at the configuration of stones on the board. Alternative superko rules may also consider things such as the player to move. The official Chinese and Japanese rules do not use superko.
and not just recapturing back one stone?
Yes, it can be harmful in chess. However, for some reason the problem seems to be more disturbing with narrow deep searches than with full-width searches (such as standard alpha-beta).If it is really general repetition and if GHI has some effects on it, than GHI would be also harmfull in chess.