The 2023 ZiPS Projection Season Is Imminent

The ghost of 18th-century statistician Thomas Bayes did not see his shadow, so we are about to launch this year’s 2023 ZiPS projections. As usual, this is a space to talk about some of the basics, answer a few common questions, and wax philosophic about the very nature of predicting baseball futures. A lot of the background can be found by reading MLB’s glossary entry for ZiPS, which gives most of the basics except for the origin story.
ZiPS is a computer projection system I initially developed in 2002–04; it officially went live for the 2004 season. The origin of ZiPS is similar to Tom Tango’s Marcel the Monkey, coming from discussions I had with Chris Dial, one of my best friends (my first interaction with Chris involved me being called an expletive!) and a fellow stat nerd, in the late 1990s. ZiPS moved quickly from its original inception as a reasonably simple projection system, and now does a lot more and uses a lot more data than I ever envisioned it would 20 years ago. At its core, however, it’s still doing two primary tasks: estimating what the baseline expectation for a player is at the moment I hit the button, and then estimating where that player may be going using large cohorts of relatively similar players.
Why is ZiPS named ZiPS? At the time, Voros McCracken’s theories on the interaction of pitching, defense, and balls in play were fairly new, and since I wanted to integrate some of his findings, I wanted my system to rhyme with DIPS (defense-independent pitching statistics), with his blessing. I didn’t like SIPS, so I went with the next letter in my last name, Z. I originally named my work ZiPs as a reference to one of my favorite shows to watch as a kid, CHiPs. I typoed ZiPs as ZiPS when I released the projections publicly, and since my now-colleague Jay Jaffe had already reported on ZiPS for his Futility Infielder blog, I decided to just go with it. I never expected that all of this would be useful to anyone but me; if I had, I would have surely named it in less bizarre fashion. Read the rest of this entry »







