You are over complicating this.
Your dictionary only needs the player name as a key, and the running total for that player as that key's value.
To add points to a player's score,
set value for key(name) in dict to (score + get value in dict for key(name) default(0)).
If you need to show scores in descending order, convert the dict to a 2 column table (name,score) using one of the dict blocks, and use one of the sorting techniques from