I am assuming most Royals Review readers have not been religiously following the season of Jake Diekman. The 36 year-old journeyman reliever started the year on the South Side of Chicago, but the White Sox quickly tired of his performance. After pitching on April 29th they stopped running him out for a while before finally DFAing him on May 6th. He left with a 7.94 ERA across 13 games and 11 and a third innings. The Tampa Bay Rays, who were the team he last pitched to, picked him up and had him pitching from their bullpen less than a week later.
Tampa Bay has become known for picking up other people’s trash and turning it into treasure. There have been several, but Jeffrey Springs was the one that has stood out recently. Having Texas and Boston give up on him, Springs ended up in Tampa and immediately put up a meh bullpen year before being transitioned into a starter for 2022. What a transition it was! He put up a 3 fWAR season and a 2.46 ERA over 135 innings in his first year as a major league starter. Now they seem to have done the bullpen version with Diekman, but way faster.
Since joining the Rays in early may, Diekman has posted a 2.08 ERA with good peripherals. His K/9 rate jumped to 13 after being 8.7 in Chicago. It’s like he turned into a different pitcher. How did Tampa Bay do this? I can’t say this is the sole explanation, but they started having him lean on the changeup more and the fastball less, which seems to be helping a lot. In Chicago he threw the changeup about 9% of the time, and since then he has raised his rate to a little over 15%. To move it 6% in that short of a time he has had to throw the changeup about twice as often as he was before.
His changeup is not a great pitch. It is in fact about league average, and always has been according to his pitch values at Fangraphs. But what is the point of a changeup? It is to make the hitter think fastball and get out ahead. If the hitter can sit fastball and be right a lot, just throwing twice as many changeups can make both pitches more effective. His fastball had negative run values in the past two seasons, and is suddenly back in positive territory this year despite the rough start to the year.
I am not going to credit all of his success to using the changeup more, but I think there is something there. He also seems to have stopped having his minimum speeds on fastballs a little higher, so he is staying closer to his peak, for instance. Still, I think Brady needs to pick his brain and see if he can incorporate any of the changeup philosophy. Last year, when he was really going well, Singer was using his changeup almost 50% more than now, although still not as often I as I think he should. This year he is going to the slider 3% more rather than the change, and it has not been working.
When the slider is doing worse, which pitch values are showing, why would you throw more of them? It just does not make any sense. He is allowing more hard contact and walking more batters just to increase his whiff rate a tiny bit I guess. If he wants to do that, baseball savant has classified 14 (0.9%) of his pitches as sweepers, and they have a 60% whiff rate. Work that into the mix more if you are wanting swing and miss. More pitches are good, even more mediocre ones, especially more mediocre ones if you don’t have overpowering stuff. Brady Singer is probably never going to be a dominant power pitcher or have the nastiest slider in the league, so he needs to learn how to mix his stuff better. Don’t let the batters feel like they have an idea of what is coming, so that when you leave a slider up, it is punished less frequently.
I would like to see Matt Quatraro bring some of that Rays mentality to this Royals dugout. At times I have heard people say Singer is stubborn and won’t necessarily do what he is told. If the manager goes over the plan with Brady and whoever is catching on a given day telling him to throw at least 15% changeups, that should take care of it. If you get to the third inning and he keeps shaking off the change, walk out to the mound and tell him to throw whatever the catcher says. If it continues, pull him out of the game. I know the pitching depth is problematic, but Yarbrough, Zerpa, and Keller are working their way back. It is time for Singer to grow up a bit, and start trying to develop beyond what got him here. If nothing else, his arbitration and free agency salaries should motivate him to be better than he has been so far this season.
We have seen Brady Singer be good before, and we all want to see him do it again. He has the ability, but it is time to start figuring out what he needs beyond the two pitches he is comfortable with. He is too old, and too far along the development pipeline to assume this is going to happen without some sort change to the repertoire. I suggest more changeups, but if the sweeper is coming along, go that direction. I am not picky. It just makes no sense to continue down the trodden path at this point.