Minnesota Twins starting pitcher Kyle Gibson isn't exactly one of the first guys who would roll off anyone's tongue as a difference maker in fantasy baseball, but that's exactly what he did after a disastrous first half.
Through Gibson's first 81.1. innings, he posted a 6.31 ERA with 1.77 homers allowed per nine innings, and despite posting a 50.7% ground-ball rate, the 38.6% hard-hit rate allowed didn't help. His other peripheral stats weren't much better, and although his 5.35 SIERA told us he was getting a little unlucky, he wasn't doing himself any favors with a 13.6% strikeout rate and 10.1% walk rate.
Once he got this all out of his system, though, Gibson looked like a completely different pitcher in the second half.
He just about cut his ERA in half (3.76), and it wasn't a fluke based off his 3.93 SIERA. He was also generating a ton more strikeouts (22.1%) while handing out fewer free passes (6.9%). A big difference came in both the effectiveness and usage of his slider between both halves of play.
The below table shows how his usage and the value of this pitch (per Pitchf/x) transformed throughout the year.
| Slider | Usage | Value |
|---|---|---|
| 1st Half | 15.6% | -7.8 |
| 2nd Half | 20.4% | 3.9 |
Out of his top-four pitches thrown in 2017 (sinker, four-seam fastball, slider, changeup), Gibson's slider produced the lowest wRC+ (81), highest strikeout rate (41.0%), and lowest walk rate (4.5%). For a hurler with an average fastball velocity in the low-90s, execution of his secondary pitches is vital to success, which he was able to accomplish after the All-Star break.