Re: [Computer-go] some general UCT notes.

2014-08-31 Thread Dave Dyer
At 02:41 PM 8/30/2014, Álvaro Begué wrote: Can you give us an idea of what types of games you are talking about? From that email I can't tell if you are looking at Connect Four, Texas Hold'em, Diplomacy, Puerto Rico or Imperium Romanum II. I am sure the your observations don't apply to all

Re: [Computer-go] some general UCT notes.

2014-08-31 Thread Rémi Coulom
On 30 août 2014, at 22:10, Dave Dyer dd...@real-me.net wrote: I've also been comparing blitz play which creates a copy of the board at top level, and starts each descent with a copy of the board; compared with unwinding play where every move is explicitly unwound. Of course, the complexity of

Re: [Computer-go] some general UCT notes.

2014-08-31 Thread Petr Baudis
Hi! Thanks for sharing your observations. On Sat, Aug 30, 2014 at 01:10:10PM -0700, Dave Dyer wrote: I found simple threading had a pretty sharp knee in performance at 4 threads. In other words, 2 3 and 4 threads improved the overall amount of work done more or less linearly to 3.5x,

[Computer-go] Probability drift functions

2014-08-31 Thread Detlef Schmicker
Hi, I try to find a way to measure the drift of the probability of a node. I am not looking for a heuristic like compare the last 1000 playouts with the probability of all playouts but something more general. I found some articles over Drift Analysis, which are used in a different way, but may

Re: [Computer-go] some general UCT notes.

2014-08-31 Thread Dave Dyer
Hi Dave, I am very surprised by this. It is certainly not the case for Go, even on 9x9. Making a copy of the board should be orders of magnitude faster than running a playout. I think the important qualification is not especially optimized for speed. The board structures used are relatively

Re: [Computer-go] some general UCT notes.

2014-08-31 Thread Dave Dyer
Hi Dave, I am very surprised by this. It is certainly not the case for Go, even on 9x9. Making a copy of the board should be orders of magnitude faster than running a playout. I think the important qualification is not especially optimized for speed. The board structures used are relatively

Re: [Computer-go] some general UCT notes.

2014-08-31 Thread Dave Dyer
Do you exclusively lock the tree when working with it, or does Java allow some tricks to use the traditional lockless tree updates? I lock each node while it is being manipulated, so threads that are in different parts of the tree are not obstructed.

Re: [Computer-go] Probability drift functions

2014-08-31 Thread Dave Dyer
Did somebody already tried this? The idea is, drifting nodes have to explored in more detail... One related observation; if the number of playouts (or time to be spent) is predefined, then at some point it becomes mathematically impossible for low-scoring nodes to ever advance to first place.

Re: [Computer-go] Probability drift functions

2014-08-31 Thread Dave Dyer
Did somebody already tried this? The idea is, drifting nodes have to explored in more detail... One related observation; if the number of playouts (or time to be spent) is predefined, then at some point it becomes mathematically impossible for low-scoring nodes to ever advance to first place.