Running very fast games in xboard

[krazyken]

Indeed, this is a problem with ultra-fast games: The incrtement gets lost in rounding. WB protocol does not allow decimals on the timing parameters.

The most practical solution is to not use incremental, but classical time control. Games on the average last 60 moves (and most engines assume this in allocating their time), so with 1:40+1 in practice you will be playing 60 moves in 160 seconds. So you could play 60/2:40 or 40/1:45 in stead. An alternative is to simply let the increment come to the engine as a (pleasant) surprise. Most of it will get lost in communication delays anyway, at this speed, so perhaps it is just as well that the engine does not count on it.

Usually adapting the engines is not an option. If it were, it would be best to forget about time, and implement the nps command in the engine to read its own node count in stead of the system clock. Then you are completely insensitive to any kind of delay, and could even play milli-second games.

That's a good idea. In my case, using classical time control will work.

I'll do something like 40 moves per 15 seconds (if it's not too fast).

I am doing right now 40 moves/20 seconds and it is fine.
make sure you run with -xanimate and 1) disable the screen saver and 2) close the folders that contain files that will be modified (for instance, folders that contain log files). In my case, Nautilus (gnome) updates the information of what the folders contain and chews some CPU time.

I estimate that running games 40 moves/4 s will still be ok but I have not tested it yet.

There were other suggestions such as running the engines with lower priority than xboard, but I have not tested that yet. There is a thread about it in winboard forum

http://www.open-aurec.com/wbforum/viewtopic.php?t=49855

Miguel

I have run games at 40 moves/4 secs before, And several engines handle this fine without ever losing on time. The thread can be found here.

[cyberfish]

I run fixed-depth matches instead, and games last about 2 seconds. About 40000 in one night using a dual-core CPU (running 2 games at a time, ponder off).