March 30, 2017
Extreme Makeover: American League Edition
On Monday, I introduced a new made-up statistic, the Change Index, to estimate how much each National League team’s hitters and pitchers are turning over. You can read all the details here, but to give you a précis, I compared actual 2016 plate appearances and innings pitched to the projections in the BP depth charts. I added the absolute values of every change (reductions in playing time and additions to playing time) and divided the result by two to get the mean. Then I calculated a Change Index equal to the change in plate appearances, plus 3.5 times the change in innings pitched, all divided by 50.
Again, you can click the link to see exactly how this calculation works and why I chose 3.5 for the pitching weight. But I do want to reiterate a caveat: Don’t take this too seriously. These numbers are highly speculative. Our playing time projections don’t anticipate unexpected injuries, or ineffectiveness, or improved play, or trades. We don’t even know all the 25-man rosters yet. (Projected depth charts used here are as of mid-day, March 29.) Nothing’s finalized, and even when it is, it’s only a guess.
As you’re reading this, somebody is getting sent down to the minors or straining an oblique or getting moved up or down the batting order, all of which will affect his playing time. The changes we’re projecting should, in general, hold true—the Rangers will definitely have to replace all 503 of Mitch Moreland’s 2016 plate appearances, and our projection of 557 plate appearances for Mike Napoli is as good a guess as any as to how—but this is mostly guesswork, if informed guesswork.
Here are the projected changes in hitter plate appearances and pitcher innings for the American League, along with each team’s Change Index.
What did Jerry Dipoto do? This offseason, the Mariners and their frenzied general manager, Jerry Dipoto, dominated the transaction log so much that our award-winning author Meg Rowley was on The Ringer MLB Show podcast, hosted by our former BP colleagues Ben Lindbergh and Michael Baumann, twice to break down Seattle’s roster moves, prompting Baumann to pen an ode (go to the 54:29 mark).