Thanks for your feedback Gunnar.

I just put up a new release, "beta2", that corrects several of the issues that you pointed out. It's at the same http://www.igoweb.org/~wms/upload URL. Comments below, with one longer followup comment in another post. (PS - Apologies for sending my previous post as HTML mail, I know that it messes up archives and bundled messages).

On Thu, 2004-01-01 at 03:00, gtp-request@lists.lysator.liu.se wrote:

| undo | If your engine supports this command, you will get it as | normal. If your engine does not list undo as a response to | list_commands, then any undos that your opponents request will | be denied, so this command is optional from kgsGtp's point of | view.

With some extra work undo can be simulated by clear_board + play commands. On the other hand, allowing undo at all has potential cheating problems. GNU Go on NNGS never accepts any undo, for good and for bad. Even if the engine supports undo it would be good to have a config option not to accept undos.

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; the only reason that I had the "no undo command, undos are declined" logic is to help people get started faster.

| final_status_list | After the game enters scoring kgsGtp will send this command. If | you return a list of dead stones, then kgsGtp will mark those | on the board. If you return an error, then kgsGtp will not mark | any stones dead and your opponent will have to do that instead.

Do you ever ask for seki stones? I seem to recall that KGS tries to identify such when Japanese rules are used.

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).

| clear_board | Used after each game to start over. If you don't support this, | then you will be limited to one game for each time you run | kgsGtp.

If you don't already do that, clear_board should be issued also at the start of the first game. Although many engines will start with an empty board that is not guaranteed.

Thanks for pointing this out. The new version does a clear_board before each game (if clear_board is a supported command, otherwise it just hopes for the best then exits after one game).

| * Free games only. Right now it has no way to argue over dead stones | at the end of the game, so if your opponent changes the stones | that you mark dead, kgsGtp simply accepts the changes. This makes | it very easy to cheat a kgsGtp player, so only free games are | allowed right now.

GNU Go on NNGS insists on adjourning the game if the opponent does not agree on dead stones. The opponent is left with the options to a) accept GNU Go's judgment, b) resign, or c) complain to me that GNU Go gets it wrong (and then I either resign the game or fix the bug, or both). The latter happens occasionally but we're talking of far less than 1% of the games.

This is probably not practical for kgsGTP and the understanding of life and death status will of course vary significantly between different engines. What could be interesting is an option to ask another engine, e.g. GNU Go, for the final status.

I don't much like the first solution because it won't work until the engine is mature enough to correctly spot dead stones. (I'm impressed with gnugo, it sometimes takes a long time to come up with the list of dead stones, but in the games I played it was right even in fairly tricky situations). As for using GNU go as the final arbiter, that's possible but still has the problem of what to do in the <1% of the time that GNU go is wrong, plus the "kludge factor" of requiring gnugo be packaged with kgsGtp even if you want to use a different engine!

I've got an idea to try for this, but it's long, I'll put it in another post.

| * Engine cannot refuse game settings. If somebody sets up a game | that is 9×9 and your engine only supports 19×19, all you can do is | resign immediately. Eventually I hope to add a kgs-specific | command that asks the engine if the settings are OK, then accepts | the game only if it agrees.

In the specific case of board size, kgsGTP should at least check whether boardsize returns an error before accepting the game.

Good idea. The new version will do exactly what you recommend.

| * No way to resume games.

I assume there are no principal difficulties implementing this and just a question of time.

Well, the one issue was that I didn't yet code it up, the other was that a bug in the server made the most logical way for people to try to resume games, fail. The server does not let you resume a game if your opponent is already playing in another; a bug in the server also prevented you from resuming if your opponent is looking for a game! Since the kgsGtp client is *always* looking for a game when it's not playing, loading was difficult. The beta2 kgsGtp release can resume games, but until a new KGS server version is released it will still be difficult to use.