In a 1v1 map consisting of 10 rounds, the player who wins, how do I make something which stores the player's id and that he has won

[SheloLemon]

In a 1v1 map consisting of 10 rounds, how do i make something that identifies that the player has won ?(the player who has won most rounds out of 10)

I want to use that(something which consists of player’s id and proof that he has won) somewhere else outside uefn…