Changes in the Pirates’ Pitch Selection

A few days ago, I finished updating the player pages for all the guys who actually played this year.  (We don’t have a link yet to the player pages from PBN, but you can access them from the soon-to-be-antiquated depth chart here.)  In doing the pitchers, I generally checked their pitch selection at FanGraphs and Brooks Baseball, just to see if there were any noteworthy changes.  There usually were, which I know what come as news to anybody here, but I thought I’d just note the changes for the staff as a whole.

What follows are the usage percentages for each pitch type for the team.  First is 2019, second is 2020.  MLB rank is in parentheses.

Fastball:  59.3% (1), 49.1% (19)
Slider:  21.0% (10), 24.6% (5)
Curve:  8.3% (25), 15.2% (6)
Change:  9.7% (22), 8.4% (27)
Cutter:  1.5% (29), 1.9% (27)
Split Finger:  0.2% (28), 0.7% (21)

So, no surprise, the Pirates threw a lot fewer fastballs.  That reduction of ten percentage points was very consistent, too.  If you check the individual pitchers, or at least the ones who pitched a lot, there’s a consistent pattern of cutting fastball usage by almost exactly that amount.  The “excess” went to breaking balls, especially the curve, which the team used nearly twice as often as the year before.  That didn’t surprise me, either, as anecdotally speaking, I had the impression for a while that the former regime often had pitching prospects drop the curve for the slider, if they threw both.  Joe Musgrove was a prime beneficiary; his curve usage more than doubled and opponents batted .050 against the pitch, with no extra base hits.

By contrast, the Pirates’ use of the change dropped a little.  It occurred to me that the new front office concluded some of the pitchers just don’t throw a good one and there’s no point in trying to force them to throw it.  An exception, obviously, was Steven Brault.  His use of the change nearly doubled and, as he said in interviews, a lot of that came at the end of the season.  (Brault credited Jacob Stallings for the shift, a development that could benefit the team more broadly going forward.)  Opponents batted .117 against Brault’s change.

The low usage of the cutter annoys me.  Considering the trouble the Pirates have had getting pitchers to throw useful changeups, the cutter always seemed like a possible alternative.  Of course, that’s a shift that probably needs to be implemented more at the minor league level, if we ever have one again.  The splitter just isn’t thrown much any more, partly because it’s been linked to arm injuries.  A handful of teams didn’t throw it at all.

I have no doubt that the shift to breaking balls had a lot to do with the team’s walk problems this year.  They had MLB’s worst BB/9, at 4.4.  Not that they were good in 2019, when they the seventh-worst at 3.7.  They had some pitchers, though — like Trevor Williams and especially Musgrove — who’ve normally had good control but who saw an increase in walk rates this year.  Musgrove’s walk rate increased by 71%.

It’s probably a necessary tradeoff.  One other thing that struck me in updating the player pages was that many of the team’s pitchers had frightening opponents’ slugging averages against their fastballs.  Opponents slugged .650 against Musgrove’s fastball, for instance, but only .050 against his curve and .283 against his slider.  Chad Kuhl gave up a .600 SLG against his sinker and .818 against his four-seamer (he didn’t use the latter much), but only .239 against his slider and .222 against his curve.  What I don’t know is how much this applies MLB-wide, i.e., Does everybody hit a ton more against fastballs?  Regardless, it’s clear that a lot of hitters just sit fastball, so the Pirates are probably headed in the right direction.

UPDATE:  I was thinking about Scott’s comment about improving command and it led me to wondering whether there was evidence of that over the (mini-)season.  The changes in pitch selection were pretty substantial and I suppose it could take some adjustment, especially for the starters.  They came in with a new regime in spring training, had that cut short a little, then had a three-month layoff.  It’s hard to say what impact that’d have.

Anyway, here’s the team’s BB/9 by month:

July (7G):  5.1
August:  4.5
September:  4.1

(The team’s K rate also improved in Sept., from 9.4 to 8.8 to 10.0.)

Of course, there were probably other factors at play that would’ve accounted for improving numbers.  The team ditched some bad pitchers, got a healthy Musgrove back, eventually assembled a serviceable bullpen (although that included Geoff Hartlieb, who had serious walk problems), and had two key pitchers (Kuhl and J.T. Brubaker) coming back from long layoffs with no rehab stints.

But there’d have to be an adjustment period, you’d think.  This is anecdotal, but it’s the product of attending a lot of minor league games:  I’ve felt that the Pirates long had a rather rigid pattern of trying to use the fastball to set up favorable counts for secondary pitches.  When the pitcher was behind, or was struggling, they’d consistently and predictably go FB FB FB FB FB.  They seemed to do the same thing at the major league level, too.  I’m sure it takes more fortitude to throw a curve or change on a 3-1 count, so there’s probably a process of selling the pitcher on it.  Of course, it’s also going to mean more walks, but that’s usually going to be better than throwing a FB to a hitter who’s sitting on one.