Search found 40 matches

by grahamj
Sun Jan 05, 2020 8:11 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Simulated game trees
Replies: 0
Views: 640

Simulated game trees

Last year I wrote some code to generate simulated game trees. I am mainly interested in algorithms like PUCT (LC0,A0) and realisation probabilities (which I've only seen used for Shogi). I'm not personally interested in alpha-beta pruning, but perhaps the simulator is of general interest. The simula...
by grahamj
Fri Jan 03, 2020 10:23 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 6038

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

But this is not a realistic "chess like" tree. In chess neighboring positions in the tree are heavily correlated. Moreover evaluation errors are also heavily correlated. Modern chess engines (A/B and MCTS) exploit these correlations. You will not capture this with a simple random tree. Generating r...
by grahamj
Fri Jan 03, 2020 8:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 6038

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

Another algorithm that REALLY sticks in my craw is MCTS. Monte Carlo, for gambling, of course. So, instead of intelligent and guided search, we cast a net blindly left right and center. Maybe it lands in the water. Maybe it lands on a tree. Maybe it catches a bunch of fish. Why should this turn out...
by grahamj
Fri Nov 15, 2019 9:17 pm
Forum: Computer Chess Club: General Topics
Topic: GPU rumors 2020
Replies: 9
Views: 1262

Re: GPU rumors 2020

I meant the host-device latencies also known as kernel launch overhead, can vary between 5ms and 100ms on different systems for null-kernels, this is primary not caused by the PCIe connection, but (speculation) by the little embedded CPU controller in all GPUs that launches the kernels, I admit the...
by grahamj
Thu Aug 29, 2019 4:34 pm
Forum: Computer Chess Club: General Topics
Topic: Lc0 Evaluation Explanation
Replies: 15
Views: 2883

Re: Lc0 Evaluation Explanation

LC0 chooses the move with the most visits. Searching the explanation for 'visits' may help.
by grahamj
Tue Aug 20, 2019 9:15 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: deepdebt
Replies: 8
Views: 2086

Re: deepdebt

Ok the company is betting on reinforcement learning but other research instititures (univ.) could explore the other avenues that could get us there. But as the author says "Every dollar invested in reinforcement learning is a dollar not invested somewhere else..." I watched neural nets being massiv...
by grahamj
Fri Jun 21, 2019 1:29 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Lazy-evaluation of futures for parallel work-efficient Alpha-Beta search
Replies: 53
Views: 15951

Re: Lazy-evaluation of futures for parallel work-efficient Alpha-Beta search

Thanks for the further details. I won't pretend I understand them yet, but your project sounds interesting. You have at least understood that the main problem with using a GPU for chess is how to implement the search tree.
by grahamj
Fri Jun 21, 2019 9:16 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Lazy-evaluation of futures for parallel work-efficient Alpha-Beta search
Replies: 53
Views: 15951

Re: Lazy-evaluation of futures for parallel work-efficient Alpha-Beta search

I am working on a GPU chess engine, but it is not like yours, and does not use alpha-beta search. I will be interested to see how you get on. I described my ideas here. http://indriid.com/2019/2019-01-06-tinsmith.pdf * Tomasulo's Algorithm -- https://en.wikipedia.org/wiki/Tomasulo_algorithm. Tomasul...
by grahamj
Wed Mar 20, 2019 2:58 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Minimax, noisy evaluations, PUCT
Replies: 1
Views: 920

Minimax, noisy evaluations, PUCT

Minimax is known to have a bias which does not diminish with depth. The paper Bias and pathology in minimax search , 2005, A. Sadikov, I. Bratko, I. Kononenko uses KRK endings to investigate this. Here's a simplified situation which I was able to analyse mathematically. Suppose the branching factor ...