How Scott Oberg became a more impactful pitcher in the second half

The Rockies bullpen took a step forward in 2018. By signing Wade Davis, getting a breakout season from Adam Ottavino, and having other serviceable relievers such as Seunghwan Oh step in and pitch them through critical innings was a large reason they wound up playing in October.

But perhaps the most unheralded relievers in the Coors Field home bullpen, and maybe one of the more unheralded relievers in all of baseball last season, was 28-year-old right-hander Scott Oberg. Many wouldn’t guess it, but Oberg was second among Rockies relievers in most statistical categories, trailing only the All-Star Ottavino.

The 2018 season wasn’t a straight line of success for Oberg, though. For much of the first half, he struggled with his peripherals and overall put up pretty mediocre underlying numbers. During that time, as it had been for most of his career, he seemed like just another reliever. The script was flipped post-All Star break, though, as Oberg provided crucial value during the most important time of the season.

To explain it clearly, here were the first and second half splits for Oberg.

• First half: 27 ¹⁄₃ IP, 2.96 ERA, 3.20 FIP, 3.63 xFIP, 18.9% K%, 6.3% BB%
• Second half: 31 ¹⁄₃ IP, 2.01 ERA, 2.59 FIP, 2.13 xFIP, 30.8% K%, 4.3% BB%

The number that stands out is without question the strikeout rate. Across three previous major league seasons, Oberg had never posted a strikeout rate higher than 20.8 percent, which he put up in 2017. The first half numbers indicated he was hovering around his career standard.

From the beginning of the 2015 season to the end of the first half in 2018, Oberg’s strikeout rate ranked 84th out of 90 relievers with as many innings as him in that time span. Look at just the second half of the 2018 season though and Oberg ranked 10th in that department out of 55 relievers with as many innings as him.

Now to what changed. There were no dramatic changes in velocity or release point. This looked to be mostly a shift in strategy. Starting with the pitch distribution (Oberg is predominantly fastball/slider, mixing in a changeup), it looked like he started relying on his four-seamer and slider a bit more, throwing the changeup less often and almost ditching the sinker. Towards the end of the season, he was throwing his slider at a higher rate than any point in his career.

FanGraphs

He threw his four-seamer and slider 78.7 percent of the time in the first half. In the second half, that rate jumped to 93.5 percent.

He even changed things up more in 0-0 counts. Again, he essentially ditched the sinker. He stopped throwing the changeup and was even more a strictly four-seamer/slider pitcher.

Looking at two-strike counts, more importantly, Oberg went nuts with his slider compared to the past. This can best explain the strikeout surge, as in the first half he only struck out nine batters with his slider. In the second half, he struck out 23 with the offering.

By any account, Oberg was more of an impact pitcher in the second half than at any other point in his career. All thanks to the strikeouts too. If these changes in pitch usage are indicative of this major surge of strikeouts, this improvement could be hear to stay. And with more question marks arriving with closer Wade Davis, the departure of Adam Ottavino, the Rockies could have little to rely on with their bullpen in 2019.

A lot of the Rockies success in 2019 came from their strides as a whole in the bullpen. To have any chance of keeping that going, they’ll need Scott Oberg and his strikeouts.

Patrick Brennan loves to research pitchers and minor leaguers with data. You can find additional work of his at Royals Review and Royals Farm Report. You can also find him on Twitter @paintingcorner.