gnus-thread-score-function

gnus-thread-score-function is a variable defined in `gnus-sum.el'.
Its value is

+

• This variable may be risky if used as a file-local variable.

Documentation:
*Function used for calculating the total score of a thread.

The function is called with the scores of the article and each
subthread and should then return the score of the thread.

Some functions you can use are `+', `max', or `min'.

You can customize this variable.