Is it possible to play against a "virgin" Leela Chess engine to see how many games it takes it to beat me? That is, can I train Leela Chess by playing against it myself?


2 Answers 2


Not an expert but you can play against a "virgin" Leela by using one of the younger nets. For example in the first Leela test (the so-called training run) the strongest net was 11248. If you play against, e.g., net 00010, it'll be much weaker.

However, you can't train Leela by playing against it. You can play against the trained product, but you can't train Leela yourself. That's because Leela is supposed to learn entirely by self-play (that's why its full name is Leela Chess Zero - "Zero" for zero human knowledge).

  • 2
    I would like to add that several people have created early Leela clones as BOTs on lichess that you can play against. So to your first paragraph: without even downloading and configuring anything, others have done the heavy lifting for you. Apr 7, 2020 at 21:24
  • 5
    Not to mention it takes an inordinate (for a human) amount of games played for it to learn sufficiently to even be making recognizably non-random moves. Apr 8, 2020 at 5:26
  • 1
    @Shufflepants I was guessing that point though
    – Olórin
    Apr 8, 2020 at 5:52
  • 1
    No one trained lc0 against an sf9-10 or 11 for instance ?
    – Olórin
    Apr 8, 2020 at 10:57
  • 1
    @Olorin No - because again that would no longer be "Zero". Still, there was a Leela derivative project named "Antifish" that did what you're thinking of, see e.g. groups.google.com/forum/#!topic/fishcooking/6ceFnzAjFQI
    – Allure
    Apr 8, 2020 at 11:30

Yes, you could in principle set up Leela such that it learns by playing against you. It would require some programming skills and a lot of time to play games.

Currently Leela has been trained on 300.000.000 games. You should expect to have to play at least a couple of thousand games against it to see an improvement.

Also, Leela doesn't learn anything if it always loses. So you either can't start from zero, or you'd have to massively handicap yourself such that you regularly lose even against the initial random play.

  • typical leela training uses ~15-30k games per net. Leela is usually GM level by net 3 or 4, so if you scimp a little on the number of games per net, you could probably get by with only 10k games or so Apr 10, 2020 at 5:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.