X X (value is hit two times)
X (value hit 1 time)
When you hit a triple and a single you have four times twenty.
You need one twenty to get the number closed.
Now you have 3 times twenty left (4-1).
Because your opponent has not yet hit the number 3 times you get points.
You get, when the value is for instance 20, 3 times 20 points (=60 points total).
Finishing the game
The player with the most points and the numbers 10 to 20 and bull hit 3 times wins the game.