What is a good method for modelling combinatorial tree (sport competition results)?
I can't follow how you get 30 combinations, you have 2 matches per journey each of the 2 matches can result in 5 different attributions, so you get 5*5 = 25 different attribution per match. At each journey there are 3 possibilities to make 2 matches. So the result would be 25/3 + 25/3 + 25/3 = 25 different point attributions.
Did I got something wrong?

You want to calculate how many different point attributions there are after n journeys and the probabilities to make a match are the same for every combination at every journey?