If there are any people with a better seat on the “Strikeouts are the lifeblood of pitchers” train than me, there can’t be many. There are many arguments about why that might or might not be true but, for me, it boils down to this: If a pitcher strikes a batter out he doesn’t have to rely on good luck or fear bad luck on a ball that has been put into play. If you’re not familiar with the term, “Seeing-eye single” it refers to a batted ball that was hit very poorly but managed to find a hole in the defense all the same. It’s indicative of a pitcher who did everything right except get the batter to completely miss and the result of the play is still a net negative for him. If a pitcher can do everything right except one thing it makes sense to prefer that one thing.
Brad Keller is not good at doing that one thing which, here, means getting guys to swing and miss.
And yet, he has been the Royals’ best starting pitcher for each of the last three years. Not merely because of a lack of quality competition, either; though that has played a part, too. Seeing-eye singles aren’t awful on their own, they represent only one base and a batter/runner needs four to score a run. Where they become a problem is when they’re added to the results of a pitcher who was relying on them becoming an out because he’s also giving up bases on walks and/or well-hit balls. Brad Keller has found success in the past three years because he doesn’t give up many well-struck balls. He became elite in 2020 because he gave up even fewer well-struck balls and also stopped walking guys.
Brad Keller is a groundball pitcher. For three straight seasons he has gotten batters to put more balls on the ground than in the air. Groundballs are good. According to FanGraphs, a groundball was worth a slash rate of .229/.229/.250 in 2020. Keep the ball on the ground and generally bad things don’t happen. Again, I want to highlight that that isn’t as good as the slash rate of .000/.000/.000 on strikeouts but, after strikeouts, groundballs are the best outcome.
However, most pitchers struggle when hitters are able to get the ball in the air. In 2020 pitchers allowed a slash of .239/.234/.756 on flyballs. You’ll note that the batting average hardly moved but the slugging percentage more than tripled. Not so for Brad Keller, who only allowed a .282 SLG in 2020. And, while he’s not been that good in the past, he’s always been a pitcher for whom flyballs regularly turned into outs. Batters have never cracked the Mendoza Line (.200) against him on flyballs and the slugging percentage against is always better than average, as well. So this seems less like a fluke a more like an improvement on something he was already doing passably well.
Keller similarly improved his walk numbers in 2020; he dropped them from a devastating 3.81 BB/9 in 2019 to only 2.80 in 2020. One peripheral statistic that isn’t talked about as much as others but but can still tell you a lot about a pitcher is K/BB ratio. A pitcher can often get away with fewer strikeouts if they’re also not giving up free passes - see Jamie Moyer and Greg Maddux for excellent examples of this. Keller’s K/BB ratio in 2019 was a pedestrian 1.74 which means batters were reaching base at a .371 clip on non-contact plate appearances. In 2020 it was 2.06 which means they were only getting an OBP of .327 on non-contact plate appearances.
So now that the improved results have been highlighted, it’s time to ask the all-important questions of whether we can figure out why and whether it seems likely to be maintained. To answer the first question we go to Baseball Savant. There we can see that the movement on Keller’s slider has improved every year he’s been in the big leagues. We can also see that he drastically increased its usage in 2020. It was a pitch he threw nearly half as often as his four-seamer in 2018 and now he throws it almost exactly as often in 2020. If we check their visualization report, we also see that Keller’s slider has an above-average RPM in 2020. More and more evidence has been discovered in recent years to suggest that a higher RPM on pitches can be directly tied to success with that pitch. And all that answers the second question, too. The usage and improvement on his best pitch have been trending up for three straight years. There is no reason to think he won’t be able to continue pitching this well.
Brad Keller is still only 24 years old. When Jackson Kowar, perhaps the best pitcher from the Royals 2018 draft class, reaches the big leagues next year he will be 24. Perhaps it’s time the Royals started seriously considering a contract extension for Brad Keller. He may defy the odds by being a successful pitcher who doesn’t get a lot of strikeouts, but there now exists ample evidence to suggest he will continue defying those odds for years to come. For his spectacular results in 2020, I award Brad Keller an A.
What grade would you give Brad Keller?
This poll is closed