Mathemadage: The Inevitable Reliever Blowup Theory

If you’ve watched a postseason game in the last decade, you’ve heard the theory. Honestly, if you’ve watched a postseason game in the last decade, you’ve probably thought of the theory yourself. When a team eschews a regular starter and instead uses a string of relievers, surely one of those relievers is bound to be a little bit off. There are just so many of them. What, they’re all going to have it? C’mon, man. Be reasonable. And what happens as a result? Well, that reliever is going to give up a bunch of runs. You know, like pitchers do when they don’t have it. Obvious!
Hello, and welcome to another edition of Mathemadage. This time, we’re hot on the trail of what I like to call the Inevitable Reliever Blowup Theory. There isn’t one specific adage to point to here, but I’ve always wondered about this effect myself, and last week Other Ben (Lindbergh) forwarded me this tweet:
I hear this every bullpen game that the risk is law of averages says one of the relievers wont have it.
I have not seen any actual study anyone has done about this. Seems like it is just passed around as conventional wisdom.
— JJ Cooper (@jjcoop36) October 3, 2026
That was a good enough excuse for me to dig in – like I said, I’ve had this on my mind for a while, and the playoffs are the perfect time for a deep dive. But before I started cracking open my spreadsheets and coding agents, I did a literature review, because I knew I couldn’t be the first person to have investigated this. Back in 2015, Henry Druschel found that starters had more “disaster” outings than relievers, though he didn’t delve into the stacking aspect of using multiple relievers in a single game. I also found former colleague Kevin Goldstein’s investigation into the subject, which focused on the Rays’ ability to avoid reliever blowups. But those didn’t settle the debate for me, so I pressed on. Read the rest of this entry »


