Here's another hypothitical for you. Based on real numbers by two different pitchers.
Player A: 3621 IP, 3.42 ERA, 100 ERA+, 4.48 FIP, 1.191 WHIP, .243 OAV, .299 OBP, .390 SLG, .689 OPS
Player B: 3659 IP, 3.23 ERA, 104 ERA+, 3.91 FIP, 1.287 WHIP, .249 OAV, .317 OBP, .410 SLG, .728 OPS
The last four items (OAV, OBP, SLG, OPS) were for hitters against that pitcher.
Who's the better pitcher?