{"action":"created","issue":{"url":"https://api.github.com/repos/SanchoGGP/ggp-base/issues/217","labels_url":"https://api.github.com/repos/SanchoGGP/ggp-base/issues/217/labels{/name}","comments_url":"https://api.github.com/repos/SanchoGGP/ggp-base/issues/217/comments","events_url":"https://api.github.com/repos/SanchoGGP/ggp-base/issues/217/events","html_url":"https://github.com/SanchoGGP/ggp-base/issues/217","id":69549030,"number":217,"title":"Network split on the wrong proposition?","user":{"login":"arr28","id":3194913,"avatar_url":"https://avatars.githubusercontent.com/u/3194913?v=3","gravatar_id":"","url":"https://api.github.com/users/arr28","html_url":"https://github.com/arr28","followers_url":"https://api.github.com/users/arr28/followers","following_url":"https://api.github.com/users/arr28/following{/other_user}","gists_url":"https://api.github.com/users/arr28/gists{/gist_id}","starred_url":"https://api.github.com/users/arr28/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/arr28/subscriptions","organizations_url":"https://api.github.com/users/arr28/orgs","repos_url":"https://api.github.com/users/arr28/repos","events_url":"https://api.github.com/users/arr28/events{/privacy}","received_events_url":"https://api.github.com/users/arr28/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/SanchoGGP/ggp-base/labels/experiment","name":"experiment","color":"5319e7"},{"url":"https://api.github.com/repos/SanchoGGP/ggp-base/labels/P2","name":"P2","color":"666666"},{"url":"https://api.github.com/repos/SanchoGGP/ggp-base/labels/T2","name":"T2","color":"444499"}],"state":"closed","locked":false,"assignee":{"login":"arr28","id":3194913,"avatar_url":"https://avatars.githubusercontent.com/u/3194913?v=3","gravatar_id":"","url":"https://api.github.com/users/arr28","html_url":"https://github.com/arr28","followers_url":"https://api.github.com/users/arr28/followers","following_url":"https://api.github.com/users/arr28/following{/other_user}","gists_url":"https://api.github.com/users/arr28/gists{/gist_id}","starred_url":"https://api.github.com/users/arr28/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/arr28/subscriptions","organizations_url":"https://api.github.com/users/arr28/orgs","repos_url":"https://api.github.com/users/arr28/repos","events_url":"https://api.github.com/users/arr28/events{/privacy}","received_events_url":"https://api.github.com/users/arr28/received_events","type":"User","site_admin":false},"milestone":null,"comments":2,"created_at":"2015-04-20T09:42:04Z","updated_at":"2015-04-20T11:03:31Z","closed_at":"2015-04-20T11:03:31Z","body":"I believe (without reference to the code) that we do the X-/O-Net split on the proposition that changes most frequently in sample playouts.  This mechanism tends to catch the control proposition because the control proposition typically changes every turn (or perhaps every other turn).  For some games though (of which Kalaha is particularly notable), we catch a different proposition instead because the control proposition doesn't actually change very often.\r\n\r\nAs I understand it, the advantage of network split is a reduction in the number of components that we need to propagate changes through.\r\n\r\nI have a hypothesis that (for best perf.) we shouldn't actually be splitting on the most frequently changing proposition.  A better approach *might* be to split on the proposition whose change is correlated with the largest change of other propositions.\r\n\r\nProbably better still, we could multiply the proposition change frequency by the average impact of changing that proposition.  (After all, there's no point in splitting on a proposition that has large impact if it basically never changes.  Although, having said that, it would be interesting to see whether we do better in w/Pie games by splitting on the pie proposition rather than the control proposition.  Probably not, but I might take a look.)"},"comment":{"url":"https://api.github.com/repos/SanchoGGP/ggp-base/issues/comments/94423387","html_url":"https://github.com/SanchoGGP/ggp-base/issues/217#issuecomment-94423387","issue_url":"https://api.github.com/repos/SanchoGGP/ggp-base/issues/217","id":94423387,"user":{"login":"arr28","id":3194913,"avatar_url":"https://avatars.githubusercontent.com/u/3194913?v=3","gravatar_id":"","url":"https://api.github.com/users/arr28","html_url":"https://github.com/arr28","followers_url":"https://api.github.com/users/arr28/followers","following_url":"https://api.github.com/users/arr28/following{/other_user}","gists_url":"https://api.github.com/users/arr28/gists{/gist_id}","starred_url":"https://api.github.com/users/arr28/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/arr28/subscriptions","organizations_url":"https://api.github.com/users/arr28/orgs","repos_url":"https://api.github.com/users/arr28/repos","events_url":"https://api.github.com/users/arr28/events{/privacy}","received_events_url":"https://api.github.com/users/arr28/received_events","type":"User","site_admin":false},"created_at":"2015-04-20T11:03:31Z","updated_at":"2015-04-20T11:03:31Z","body":"In Kalaha, the automatically chosen proposition is \"hand north s0\".  Splitting on \"control north\" instead gives performance ~1% better (probably within measurement error).  The X-Net grows ever so slightly with the hand-picked split prop (50,694 vs 50,680 originally) and the O-Net shrinks substantially (36,437 vs 46,468 originally) but the smaller O-Net hasn't significantly improved performance."}}