The Death of the Complete Game
A generation ago, a starting pitcher who left before the ninth had failed. Today complete games are rare. Teams discovered that a starter’s effectiveness drops sharply the third time he faces a lineup — the times-through-the-order penalty — and that a fresh reliever throwing max-effort is usually the better bet.
Leverage and Roles
Modern bullpens are built around leverage: the closer for the ninth, set-up arms for the seventh and eighth, and matchup specialists for a single dangerous hitter. The best teams deploy their highest-leverage relievers when the game is actually on the line, not by rigid inning.
The Opener
Some teams now start a reliever — an ‘opener’ — for one inning to face the top of the order, then bring in a bulk pitcher. It is a direct exploitation of the times-through-the-order math.
Why It Moves a Projection
Bullpen fatigue is one of the most predictive and least visible factors in a game. A team whose top three relievers all pitched yesterday is far more vulnerable late, and the Ra model tracks recent reliever usage closely when it sets an expectation for the back innings.