Bill James Handbook Excerpt: Injury Update

The following essay is an excerpt from The Bill James Handbook 2022, which is available at bookstores now and can be purchased at ACTASports.com.

The book features essays, stats, leaderboards, and much more. It's more than 600 pages of baseball goodness!

by ALEX VIGDERMAN

Orioles center fielder Cedric Mullins wildly outperformed expectations in 2021. You might hear more about that in the Bill James Projections recap later in the book, because he hit for an OPS nearly 200 points higher than what we projected him for, going 30-30 when we projected him for fewer than 30 total homers and steals.

Yes, Mullins improved a great deal as a hitter. But the reason Mullins was able to put up an MVP-caliber campaign is that he stayed on the field. He appeared in 159 games, which was more than his career total up to that point. Two other AL MVP candidates through the first month of the season, Mike Trout and Byron Buxton, couldn’t say the same.

Mullins led the league in defensive opportunities as an outfielder, saved runs at a representative rate for a center fielder, and did so with one of the lowest rates of dives, slides, and jumps, which look great on highlights but are big factors in injury risk among outfielders.

He (literally) outran his projection of being one of the likeliest position players to suffer an IL-worthy injury in 2021, per last year’s Handbook.

The same could not be said for most of his comrades on those lists. We listed 10 pitchers and 10 position players who our model found to be most likely to suffer an injury and miss at least 10 days in 2021, and seven players on each list endured such a fate. That includes Spring Training losses like Mike Clevinger’s Tommy John surgery.

How are we going about projecting something as timeless in its unpredictability as physical injuries?

Well, we have collected and aggregated injury data for some years now. It started with just noting when a player suffered some kind of injury event during a game: getting hit by a pitch, pulling up lame while beating out a groundball, or crashing into the wall on a deep fly.

We combine that information with Injured List stints and media reports to create as comprehensive an injury history as anyone outside an MLB organization has. And starting in 2020, we began leveraging that data to investigate injury risk.

If you read last year’s edition of this book, you’ll recall John Shirley’s introduction to the model we built and the different elements involved. In short, we take injury data and combine it with playing time, position, body type, and play style information to create a daily estimate of how likely a player is to suffer an IL stint or miss at least ten days with an injury over the next week, month, two months, and season.

For more info on the model, its inputs, and the kinds of insights we’ve already gained, check out our presentation from the 2021 SABR Analytics Conference.

So, who are we most concerned about heading into 2022?

As of the end of the 2021 regular season, here’s who we have our eye on.

Pitchers With The Highest Predicted Injury Risk - Entering 2022

Alvarado, Stanek, Fairbanks, and Castillo were Rays teammates two years ago, and they have eight IL stints between them in the two years since. Perhaps it’s not a coincidence that only Fairbanks remains with the team.

Fans of power pitching shouldn’t be surprised to see some favorites on this list given the risks associated, but some of the more compelling pitchers to watch over the last few years have warning signs for missed time in 2022.

Chapman and Kopech have arguably the fastest fastballs of all time. Scherzer is on the back side of his career (pun intended); he has served time on the IL three times with a back injury over the last three seasons.

Hitters with the Highest Predicted Injury Risk - Entering 2022

What you should notice from the hitter list is that three big risk factors for injury are playing an up-the-middle position, being a bulky corner player / DH, and failing to discover the Fountain of Youth.

Alcides Escobar hadn’t played in the majors for two years but has already re-signed for a one-year deal with the Nationals, who gave him a bit more than a coffee this season. He doesn’t have a dramatic injury history, but his position and age make him something less than a sure bet in ‘22.

Salvador Perez and Xander Bogaerts would be huge losses to their respective teams if they were to miss time.

Perez missed 2019 to injury and after the short 2020 season was able to start 160 games (120 at catcher) this season. That’s not something we expect to continue in 2022.

Bogaerts has played in at least 136 games in every full season of his career, so it’d be a turn for the surprising for him to miss a big chunk of time, but he plays a tough position and his mix of size and just-past-his-prime age make for a cocktail of injury risk.