On which round did the team get the highest score?

The highest score will be the greatest sum of the two players
So let us find the sum of each round
The team score for 1st round = 2 + 10 = 12
The team score for 2nd round = -5 + -15 = -20
the team score for 3rd round = -5 + 2 = -3
The team score for 4th round = 8 + -4 = 4
(-v) means lost (+) means win, then
The highest score in the 1st round