Pablo López wasn’t going to stay down forever. Although he struggled at the season’s onset and sported a 5.25 ERA after his first 11 starts, he settled into form in July and August.
The Minnesota Twins’ ace struggled to consistently locate his secondary pitches in the “shadows” of the zone, and he left plenty of four-seamers down in the zone where they are the most hittable.
However, since July 10, López has posted a 2.27 ERA in 10 starts. His improvement is coming at the perfect time, with Minnesota still fighting for a Wild Card spot, if not the AL Central title.
The Twins have received plenty of support from younger arms like Simeon Woods Richardson, Zebby Matthews, and Bailey Ober, especially after Joe Ryan’s injury and the possibility that they’ve also lost Chris Paddack until October.
López is giving Minnesota confidence that it’ll have its ace in true form in October, with much of that confidence stemming from the success of his four-seamer.
Typically a 95 mph offering, López threw his four-seamer an average of 95.6 mph in August and 96.8 mph on his start against the Tampa Bay Rays on September 5.
Not only has he thrown the pitch harder, he’s thrown it more frequently.
After hitting a monthly low of a 33.6% usage rate in May, López’s four-seamer gradually climbed up in usage each month before peaking at 46.9% in August. Despite the heavy usage, López has been able to quell any decrease in performance.
Threefold, López has located the pitch up in the zone more often, where they’re more likely to succeed.
Below are graphs created using Brooks Baseball’s Profile Card tool that illustrate this change:
The benefits of this altered four-seamer usage are best understood by the chase rates of his secondary pitches.
In May, López’s sinker wasn’t retrieving the results he needed. In the past, López used his sinker beautifully as a jammer inside to righties, but he left too many over the heart of the plate to start the season.
An impressive pitch by MLBPitchProfiler’s Stuff+ metric (121), López’s 94.5 mph sinker is nasty on its own. When located inside against a righty, hitters expecting the pitch to stay “flatter” like his four-seamer have little power when the sinker darts inwards. The result is often a weak grounder or a foul ball.
It’s not that he wasn’t trying to jam hitters the whole time. But he’s located the sinker better since July 10.
The graphs below show a slight shift in pitch location, most notably inside the plate.
Fewer sinkers in the middle-middle section of the zone and the outside third of the zone have been key, and a higher concentration of pitches inside the plate has been perfect for forcing grounders and foul balls.
That change alone could’ve helped propel López. But combined with the improved four-seamer locations, his four-seamer/sinker duo creates almost unwinnable situations for hitters.
López doesn’t throw his sinker often, making up roughly 7% of all pitches he throws. With hitters keyed in on his four-seamer more, which has seen improved velocity and locations, hitters are rarely ready for López’s sinkers.
That four-seamer/sinker relationship is by no means new, and it’s something Joe Ryan implemented into his arsenal this season. Still, López has executed the pitch pairing perfectly lately.
The pitch’s increased effectiveness can be seen in the following charts, which you can find on BaseballSavant. The downward trend on the right side of each graph is simply due to a small sample size (one game) in September.
López’s ground ball rate has improved from 39.6% in the first half of the season to 50.3% in the second half. The sinker is having a profound impact on López’s resurgence.
Much like the pairing of his four-seamer and sinker, López’s changeup has improved greatly since the tumultuous first two months of the season. It reached a 49.2% chase rate in August after bottoming out at 29.4% just two months prior in June.
You can see this in the chart below via BaseballSavant:
As was the case before, the downward trend in September is nothing to worry about (yet).
His improvement in chase rate is likely related to the same four-seamer locations that helped López’s sinker. With more hitters having to respect his high four-seamer, they may be ill-prepared to adjust their eye level to a changeup that is low and out of the zone.
Most importantly, López seems to be making competitive pitches. He isn’t throwing changeups too far out, as evidenced by the pitch’s 41.7% shadow percentage.
With a sweeper that has remained dominant and a curveball, he mixes in, figuring out the rest of his arsenal has put López back in control, giving him a full array of pitches to attack hitters.
The Twins may not know who will play each infield spot or who will comprise the bullpen in October. Still, they will have their ace close to the peak of his powers.
