I have 30 years of sports data. Team A vs Opponents (B-Z) with final scores and outcome (W,L,T) I am interested in seeing how many time Team A has beaten individual opponents

Team A has beaten Team G 37% of the time
Team A has beaten Team K 12% of the time.

Any clue on which type of formula to start with? I have used the COUNTIFS, but i'm not sure if thats what I am after.