With the 2022 regular season over, it is that time where we go back and take a look at the players who appeared for the Texas Rangers this past season.
Today, we look at relief pitcher Brock Burke.
One of the clear success stories of 2022 was Brock Burke. After undergoing shoulder surgery that cost him all of 2020, Burke spent the 2021 season in the Round Rock rotation and was not good, putting up a 5.68 ERA in 77 innings over 21 appearances. Over the course of the 2021 season, we wondered why he was still on the 40 man roster, and he seemed like a potential candidate for the waiver wire in the 2021-22 offseason.
Instead, Burke came to spring training, won a spot on the Opening Day roster, and spent the 2022 season as one of the Rangers’ best pitchers. Burke ended the year with a 1.97 ERA over 82.1 innings in 52 games, and even tied for second on the team in wins, with 7. Not bad for a guy we wanted off the 40 the previous year.
And that 1.97 ERA was after fading a bit to end the year — Burke had a 1.11 ERA in early August, before putting up a 3.86 ERA and 5.45 FIP over his final 16 appearances, including allowing runs in his final three appearances of the season.
Burke relied heavily on his fastball in 2022, throwing his four seamer 63.2% of the time, with Statcast saying he also had a seldom-used sinker he threw 3.7% of the time. Against lefties, Burke went almost exclusively fastball/slider — Statcast has Burke throwing just two changeups against lefthanded hitters in 2022. Righthanders saw sliders and changeups in roughly equal amounts. Interestingly, his strikeout pitch against both lefties and righties was primarily his fastball — he had a lower wOBA and xwOBA allowed against the slider and changeup, but got Ks a higher percentage of the time with his four seamer.
In looking at the peripherals, Burke was good in 2022, though not the sort of good you would expect to result in a sub-2 ERA. Burke was in the 77th percentile in K rate, around average in walk rate, and gave up one home run every nine innings, more or less — solid numbers, but not the expectancy of microscopic ERA numbers.
And in fact, that is reflected in the defense-independent stats — in 2022, Burke had a 3.29 FIP, a 3.49 xFIP, and a 3.31 xERA. That split helps explain why Burke had a 2.1 bWAR in 2022, and a 0.9 fWAR, since bWAR is based primarily on runs allowed and fWAR is based primarily on FIP.
In this sort of situation, one would normally expect to see a big gap between Burke’s wOBA allowed and his xwOBA, similar to that between his ERA and xERA. That would indicate that Burke was benefitting from good fortune on balls in play being turned into outs. And Burke had a .266 BABIP in 2022, which would seem to suggest that as well.
However...that is not the case. Burke allowed hitters a .278 wOBA in 2022 (compared to a league average of .316). And Burke had...a .284 xwOBA in 2022. Batters were getting on base, making outs, hitting for power, etc. about what would be expected, given the quality of contact they were making, along with the walks and Ks. Hitters facing Burke had a .219/.362 xBA/xSLG against him, compared to an actual .211/.356 BA/SLG.
So what gives?
Brock Burke was extremely successful at keeping runners on base from scoring against him. With no one on base, Burke allowed a .257/.296/.453 slash line. With runners on base, he allowed just a .143/.244/.210 slash line. He walked more batters with runners on base, despite facing a third more batters with the bases empty, and while his K rate was the same, of the nine home runs he allowed on the year, seven were with the bases empty. Burke allowed 20 extra base hits in 189 plate appearances with the bases empty, compared to just four extra base hits in 139 plate appearances with runners on.
The upshot is that baserunners allowed by Brock Burke in 2022 were stranded 83.8% of the time. That put Burke in the top 10% in strand rate among MLB pitchers in 2022. Hitters might get on against him, but they weren’t going to score.
This made me curious enough to look at the breakdown between his actual and x stats in those situations. With no one on base, Burke allowed a .307 xwOBA in 2022, compared to a .323 wOBA. With runners on base, Burke allowed a .251 xwOBA, compared to a .213 wOBA. So yes, some of that is good fortune in regards to balls in play, but he also was much better in regards to the quality of contact allowed in those situations.
So that’s weird. And arguably isn’t terribly relevant, since it isn’t like one should expect that sort of dichtomy to continue in the future.
But it was interesting, at least to me. And really, isn’t that what matters?