One of the trickiest parts of writing in-depth baseball analysis is trying to navigate what is legitimate and what might just be a flash in the pan. It's not always as clear cut as one would think.
It’s why so many of these early season Mound Visits came with a “small sample size” disclaimer. To serve as a reminder that these results will likely fluctuate. Hopefully not to a point that the analysis is invalid or doesn’t hold up over the course of the whole season, but enough that you can’t go to the bank saying that a certain player will perform at that level, good or bad, for the entire season. That’s just not how baseball works.
This past week the Pirates crossed over the one-third mark over the season, and they are on the cusp of playing their 60th game of the season. If that’s enough games to base last year on, then we really can’t call it a small sample size anymore. The sample is fairly large now.
The general rule of thumb is that if a player is performing well at this stage of the season, they are probably going to finish with a good year to put on the back of the baseball card. It doesn’t look like the wheels are going to fall off Bryan Reynolds anytime soon,but we also know Ke'Bryan Hayes won't continue to be a .370 career hitter, and enough of a sample size has been built that if someone does slump for a bit, like Richard Rodríguez has of late, the overall stats reflect what they did earlier in the year.
But there are subsets of that data that could signal how a player will perform the rest of the season. A key split. A change in approach that may not be properly reflected so far. One individual pitch that’s doing much better than it had in the past, or a tool in a player’s game that has surprisingly regressed.
That’s what we’re going to dive into here today. These four players have something lurking behind their Baseball Reference pages that could influence the rest of their season, not to mention the Pirates’ success. Or maybe it won’t. Is there anything to these intentionally selected small sample sizes?
POLANCO’S MASSIVE SPLIT
While Gregory Polanco’s results have improved from last year’s low, they’re still far from good. His walk rate is up and his batting average on balls in play has skyrocketed from an anemic .193 to a bad, but livable, .275. But his strikeout rate is still over 30% and his isolated slugging mark has dropped to .145, the lowest it has been since 2017. He’s had a few bursts this year, but not early enough.
These last two seasons for him have been filled with wild splits and statistical outliers, but the one he has going this year is very unlike Polanco. It’s also pretty simple. Here’s Polanco in one specific situation:
.244/.323/.419 over 96 plate appearances
That's a pretty good slash line. And here he is in the alternative:
.164/.224/.274 over 85 plate appearances
That's pretty horrible. So what’s the split? The first is when the bases are empty. The other is when there is a man on base.
For all of the justifiable criticisms about Polanco at the plate over his career, this has never been one. Even last year he was a respectable hitter when there was a man on base:
There’s a reason why, in years past, the Pirates’ offense usually started clicking when Polanco did. A lot of those hits would come in run scoring opportunities. This year, he isn’t cashing in on those chances.
IS THIS LEGIT?: Granted, Polanco’s on-base split is over a sample size of 85 plate appearances this year, a far cry from the nearly 900 plate appearance sample from 2015 and 2018. And it’s not like there’s something obvious in his mechanics that indicates he is pressing.
“[I] haven't significantly noticed anything,” Derek Shelton said. “It's probably too small of a sample size to make anything of it right now.”
But for someone who has been batting cleanup more recently, a .132 batting average (5-for-38) with runners in scoring position isn’t going to lead to many runs. And if he doesn't start producing runs consistently, his career is going to be in serious jeopardy.
KUHL’S NEW APPROACH
Chad Kuhl has been the subject of several Mound Visits, and most of the analysis surrounding him led back to a basic thesis. His breaking pitches are quite good, the sinker and changeup were not, and a change in pitch mix could potentially lead to a breakout.
He got off on the wrong foot this year, though he did miss a good chunk of spring training going back home for the birth of his child and going through the COVID-19 intake process. He went into the regular season not fully stretched out, and by the time he was, he hit the injured list with shoulder soreness shortly after. That doesn’t excuse how Kuhl’s first couple starts, but it does help explain what happened after he appeared to take a step forward in 2020.
Keep that in mind when you see how Kuhl is attacking hitters this year. After upping his breaking ball usage last year, Kuhl has dialed it up to 11 in 2021 with the slider. Over his career, here are the outings where he has thrown the highest percentage of sliders:
His first two games back from the injured list have been the most and third-most he has ever thrown a slider in a single game. Five of the top six games where he used the slider the most have come this year, the one exception being a 28-pitch outing in 2020.
“It’s one of those pitches where if it’s 2-0 or 3-1 or 3-2, I feel like I just have the confidence, even when I’m behind in counts to throw the slider at any time, get [swing and miss] action or just throw it for strikes,” Kuhl said Sunday.
IS THIS LEGIT?: Kuhl is currently throwing his slider 41.6% of the time, the fifith-most out of starters with at least 20 innings pitched this year. Obviously that’s high, but not much more than what JT Brubaker is throwing (36.3%). This pitch leaderboard is kind of a mixed bag, but the top two pitchers in slider usage are quite good (Clayton Kershaw and Huascar Ynoa), and there are plenty of other pitchers who have had success with this slider-heavy strategy in recent years (Patrick Corbin, Kenta Maeda, Jon Gray and Madison Bumgarner, to name a few). So as a proof of concept, yes, a starter can get by throwing a slider about as often as a fastball.
Will Kuhl’s slider work at this volume? It has a chance, on the condition that he can keep it in the zone. The idea is to rely on that pitch more rather than the fastball. If he gets into too many fastball counts, it’s only going to make a poor pitch play worse. He had control problems early this year, but he’s walked only one his last two starts. This might be a way for him to turn the corner.
A NEW SLIDER EMERGES?
Let’s dive into another slider.
After hanging on through the change in team leadership in 2020 and earning a roster spot again this spring, Clay Holmes is finally showing exactly why Ben Cherington, Shelton and Oscar Marin didn’t give up on the right-hander.
Through his first 26 ⅓ innings, Holmes has pitched to a 2.73 ERA with 25 strikeouts. He had to chip away at that ERA after allowing five runs in a disastrous early outing in Cincinnati, but after a shaky start, he has not allowed a run since the end of April and gone 13 consecutive scoreless outings.
Holmes always had a power sinker and a high-spin curve, and while he has gotten very good results with both pitches, it’s the slider that has taken a huge step forward.
In 2019, Holmes threw his slider just 12% of the time, going by Baseball Savant’s data. This year, he’s upped that usage to 31.5%, and it’s easy to see why. Batters are hitting just .189 against it with a .243 slugging percentage.
The batted ball data is even better. Going by expected stats -- which is based on exit velocity, launch angle, strikeouts and walks -- his expected average is .163 with an xSLG of .197. The expected wOBA on his slider is just .189. The only pitches in any Pirates’ arsenal with a lower xwOBA are David Bednar’s splitter (.180) and Kyle Crick’s slider (.182).
IS IT LEGIT?: Unsurprisingly, a big reason why Holmes' slider is playing so well is because he isn’t leaving it over the plate anymore. Here is where his sliders landed in 2019:
Compared to 2021:
Not only is that more run and movement, but he's also away from that dreaded middle-middle spot.
“The filth of the slider has come a long way,” Holmes said recently. “It’s a pitch I feel very confident in. I like the movement profile, like the ability to get back into counts and throw for strikes, generate swing and miss when I need to.”
Holmes has dived deeper into his mechanics in recent years, and it’s starting to show on the field. He always had the tools, but now he’s executing his pitches consistently. If he can do that, then he could stick in that quietly very good bullpen.
FRAZIER’S GLOVE NO LONGER GOLDEN?
Last year, Adam Frazier had a down year at the plate but finished runner-up for the Gold Glove, saving his WAR. This year, he has been arguably the best hitting second baseman in all of baseball, but his glove has been terrible.
Baseball’s a funny game.
If the Pirates could somehow combine this year’s version of Frazier at the plate with the defender he was last season together, they would have a surefire All-Star and maybe even someone who gets down ballot MVP votes. Out of 120 defensive position players with enough innings to qualify, Frazier’s -5 defensive runs saved (DRS) are tied for the eight-worst in all of baseball. Last year, he had +6 DRS at second base.
That’s an 11 run swing. If 10 runs equates to one win over the course of the season, then we can safely say that Frazier’s drop in defense has cost the Pirates at least one game this year. He’s more than made up for it with the bat, but it’s fair to expect Frazier to have done more given his track record.
There were some concerns with Frazier’s glove before his first full year as a starter in 2019, but after back-to-back Gold Glove nominations, it was safe to assume that was behind him. Frazier is going to be one of the best position players available come the trade deadline. If he’s still having trouble in the field, it could greatly hurt his trade value, or make teams view him as a utility player first.
IS IT LEGIT?: The bad news for Frazier is that it might be too late for him to get his defensive stats to a point where he earns a third straight Gold Glove nomination. The good news is we’ve already started to see him get back to his defensive game in recent weeks.
There is no clear-cut best defensive analytic, but as we get a better understanding of how to properly value defense, the trend is that we undervalued making the routine play for years. Not routine as in it’s hit right to the fielder and they lob it to first, but the play that has a 90% out probability. One where a fielder has to take a couple steps and maybe put something on the throw. Something that, off the bat, should be an out, but is actually converted into one.
That was Frazier’s greatest defensive strength. He didn’t make many SportsCenter worthy plays, but he didn’t screw up the easy ones. I usually groan at evaluating infielder defense bases on errors, but in Frazier’s case, it’s good shorthand. He made four errors in April. He’s made one since the start of May. He’s back to doing what makes him a good fielder. He might not save his season DRS, but his glove shouldn’t scare teams away.