On Thu, 2004-01-01 at 10:50, Gunnar Farnebäck wrote:
Bill wrote:
Good point. I may get to this some time, but for now I'll just hope that most engine authors have "undo" implemented. I think it shoud be common, it is listed as one of the "required" commands;
Where do you find it listed as required? The draft spec has this to say about required command:
Sorry, my mistake. I saw undo was in the "core play commands" section, and got that confused with "required". kgsGtp beta 3 will do undos by clearing the board if undo is unsupported or if an "undo" command fails.
That's fine with me, but I still think there should be a way to decline all undos even if it's implemented by the engine.
When rated games are added, all undos will be declined for rated games only. For free games, it seems not so important. I may add a "decline all undos" option at some point though.
KGS never needs to ask for seki stones. Once you know which stones are alive and which are dead, finding seki eyes becomes quite simple, so the server does that automatically if it has to (that is, if you are using Japanese rules).
Ok, then that's not much of an issue. I thought I had read somewhere that KGS could use a bit of hinting from the players regarding sekis, but maybe I misunderstood or misremembered.
(On a side not I don't quite agree that identifying sekis given knowledge of which groups are dead is easy. It's easy in common situations or when the dame are completely filled, but for more obscure positions it may require relatively sophisticated connection analysis. Or maybe you have come up with a smarter algorithm than I did some years ago. Are the details of the KGS algorithm published somewhere?)
You *sometimes* have to fill dame, but not usually. The algorithm is described at http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=30F01D32... (it's an old rec.games.go post). An example of when filling dame is required is also present. A few people have said that this algorithm can't possibly work, but so far nobody has come up with a position that it judges incorrectly. CGoban 1 and CGoban 2 both use the same algorithm also, so to test it, just start up cgoban2, created a new SGF file, set up a position, and hit the "scoring tool". By the way that territory is marked, you will be able to see what it thinks is/is not a seki. You must mark dead stones correctly though - if there is a mistake there, it will often be confused about sekis. (You can also use cgoban 1, but I think I remember fixing a bug in the algorithm that would make the it go into an infinite loop after I stopped supporting cgoban 1).