manually changing the probability of a variation in a study

"The probability can be changed manually by adding a comment in the move with the format prc:<number>, where the number is a percentage between 1 and 100."

I put in the comment of the main move prc:<90>, but it does not seem to work.
I still get about 50% of the time the variation move, when I only want it to happen in the interactive play 1 out of 10 times

what am I doing wrong?
thanks!
Dan Mintz

We've discussed this in the chat, that is why I have not replied here. But just for all of the others: the syntax notation in the User Manual is similar to command line syntax notation. <something> means it's a mandatory value, [something] means it's optional and "something" means the value of the text "something".

So above "prc:90" is the correct usage. The angular brackets are there because the numerical value (90 in this case) is mandatory. "prc:" is not a valid command.

What is the normal probability when you don't enter any percentage? Evenly divided over the amount of lines? Or is there a probability distribution based on the length of the line? Or perhaps based on the seniority within the PGN? (Mainline vs Sideline)

Hi! And thanks for the question.

> There is a mechanism to choose what the computer will play next as your opponent. It uses the number of branches in 8 ply (4 chess moves for both players) to determine which is more probable. This value can be changed (see Next move probability depth feature) For example if you have something like 1. e4 (1. d4 d5 2. Nc3 (2. Nf3)) 1... e5 2. Nf3, the mechanism will see that there are two possible branches for d4 as opposed to one for e4, so it will choose d4 66% of the time. The probability can be changed manually by adding a comment in the move with the format prc:<number>, where the number is a percentage between 1 and 100. (ex: prc:90) Also, if set in the Transpositions behavior feature, the moves can be picked from moves following transposing positions.

quoted from siderite.dev/blog/lichess-tools---user-manual#extendedInteractiveLesson