Making sense of Royal Leela's comments

Eg. Variation: 9.91% (MC 18.00% VN 0.02%) 464 playouts

Can anyone help me understand what they mean?

My understanding:

Variation - Current win rate
MC - Monte Carlo ??
VN - Virtual Network ???
Playouts - Number of sequences tried for the position?

I find it interesting how the number of sequences tried is not proportionate to the stage of the game, i.e. lesser playouts as less moves on the board. My playouts can jump up and down wildly throughout the game pretty much every move. Unless of course my interpretation is wrong.

Also anyone know if the actual Leela program gives out analysis after every few moves or so or one must manually click the analyse function every move.

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“What do the columns in the Analysis Window mean?”

You can go read the rest :slight_smile:


Ah Thank you! Not exactly the same terminology though ._.

My eg. was from the 1 run on OGS.

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You mostly had it yeah, MC is the monte carlo win rate at the end of the primary variation. Value Network is the neural network estimated win rate for that variation.

Playouts is the # of simulations ran down the branch that is bring printed. It isn’t the total explored, but I didn’t want to make the chat message even longer. You’ll see when playing Leela using the GUI that she sometimes changes her preferred move over time. So a lot of work may have been done on a prior move that ended up not being played, making Playouts lower than move than in other moves.

If you see a number that is super low, it might be a ‘snap’ move where the policy network (a neural network predicting the most likely move a human pro would make) is so strong, Leela just makes that move herself without searching.

When you run Leela’s GUI, open the Analysis window and start Analysis, and it’ll constantly be updating while you play. The terminology I use on OGS is more similar to what gets printed out while running in bot mode, than what the columns are named in Analysis window in the GUI.


What better answer than for the person running RoyalLeela himself answering! Thank you for the explanation for technically unaware me. I actually enjoy long answers but I don’t want to eat up too much of your time either. Thanks again for running the bot as well as answering!


My pleasure. Ask me anything. Has been so much fun running the bot and refreshing my old programming skills.


how did u program Leela?

I"m not Leela’s author, he’s over at

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