The Friday File: With data showing pitcher performance declines considerably when facing opposing batters for a third time, innings pitched by starters is averaging just 5 1/3 innings. This makes relief pitching critical. And, because relievers on average pitch to just 4.5 batters/game because data says they should pitch hard and hold nothing back, teams now have 13 pitchers; just 12 position players. Until recently, teams had 10 pitchers.