Lookup value to the right of a cell repeatedly?

Hi all.

What I'd like to do is to sum the points gained in all tournaments for each player (ergo have the formula lookup the player name each time it appears, looking at the value next to it, and adding it to the sum function), while also having a dynamic sumrange, as new tournaments are guaranteed to be added in the future.

I've attached an Excel file below with three sheets: "Ranking" - Empty example with missing formula, "How I would want the ranking" - What the ranking would look like if the correct formula was implemented, and "Tournaments" - The sheet with all the tournaments.

The ideal formula would be a sum function that looks through "Tournaments", and for every time it finds the name, it adds the value to the right of that name to the sum function.