Brad Keller: Sliding into Relevance

Just a brief dispatch this week from the trenches of The Great Fantasy Baseball Invitational, where the elite meet to compete and tweet, and where the Birchwood Brothers, for the first time in history, drafted a pitcher in an early round. (We drafted third and took Max Scherzer.) We will no doubt have more to say about our draft results in the upcoming weeks, but if you just can’t wait, check out the pulse-quickening action in our league, and all the others, here, and share your thoughts with us.

Despite the all-absorbing interest of TGBFI, we would be remiss in failing to call your attention—and that of our opponents, though they probably know this already—to Brad Keller. His NFBC Average Draft Position of 413—in other words, he’s a reserve-rounder—strikes us as verging on criminal lunacy. We found our way to him the same way we found our way to Blake Snell last season (we didn’t get around to writing about this, so you’ll have to take our word for it). We looked for (1) young pitchers—under 26 and in no more than their third MLB season—who (2) pitched at least 50 innings in both halves of the preceding season, and (3) significantly increased their rate of inducing swings at pitches outside the strike zone while (4) simultaneously decreasing hitters’ contact rate on pitches thrown outside the strike zone. Our hypothesis is that this betokens an increasing ability to fool hitters with bad pitches, which—especially if, unlike Snell but like Keller, you aren’t a strikeout machine—conduces to success.

So here are Keller’s numbers: In the first half, he had an O-Swing rate of 28.0%, which was the 28th lowest out of 160 pitchers with 50-plus innings. His O-Contact rate was 67.7%, which was 55th highest. In the second half, his O-Swing rate was the 27th highest of 118 pitchers. His O-Contact rate was 63.6%, which was midpack: 55th lowest.

Fairly extreme, right? So what might have brought this change about? You have here an 8th-round draft choice out of the enchantingly-named Flowery Branch High School who had successive mediocre seasons in 2016 (high A) and 2017 (AA), and was then chosen in the Rule 5 draft by the Reds, who swiftly traded him to the Royals because the Reds of course don’t need pitching. In 2016, Baseball Prospectus characterized Keller’s changeup as “inconsistent” and his slider as “always bad.”

As so often before, Jeff Zimmerman of Fangraphs has figured out the answer. He notes, in his brief profile of Keller, that Keller’s second-half improvement is attributable to “improving the effectiveness of his slider.” We add to this the interesting facts that (1) Keller entered the Royals’ rotation only at the end of May, that (2) thereafter, he ranked 48th of 106 pitchers Third Time Through the Batting Order—not magical, but not bad, and that (3) despite switching from reliever to starter, he increased his strikeout rate in the second half.

So what we’re seeing is a guy who figured out that, to thrive as a major league starter, he needed a good pitch beyond his already-good sinker, and then developed and deployed it over the course of the second half. Let’s suppose that you get from Keller throughout 2019 what you got in the second half of 2018—not a completely implausible supposition, correct? You will get 154 innings with a 3.04 ERA, a 1.25 WHIP, 14 wins, and about 7 strikeouts per inning. Cut the wins in half to account for the fact that he pitches with the Royals and that’s still worth $10 or so. Really, folks—are you so allergic to lowish strikeout rates that you’d rather have, say, Jake Odorizzi (ADP 374)? We bet you the Royals wouldn’t.