It’s not uncommon for a pitcher to experience difficulty as a starter, move to the bullpen, and benefit from almost immediate success. That’s a story we’ve heard plenty. We’re seeing it in Arizona right now, for example — with both Archie Bradley and Jorge de la Rosa — but they’re hardly the only cases. Bullpens are littered with failed starters. The best relief pitcher ever began his major-league career with a collection of uninspiring starts.

In Anaheim, though, we might possibly be witnessing a more rare type of story. Right-hander JC Ramirez is working as a a starter right now — for the first time since Double-A in 2011, actually — and, well, there are plenty of reasons to think he’ll be a good at it. Dude’s posting the best strikeout rate of his career, and it makes sense when you look under the hood.

As a reliever, Ramirez was mostly fastball first, slider second. He threw his four-seam fastball 61% of the time and his slider 25% of the time. The first was fast but straight, and the second fast and average in terms of whiffs. It all added up to a meh swinging-strike rate (9.5%, while average for an AL reliever last year was 11.1%) and strikeout rate (16.3% against an average of 22.7%).

JC Ramirez 2016 Pitch Mix Judged by Percentiles Pitch Spin Horizontal Move Vertical Move Velocity % Used Four-Seam 31 7 8 93 61% Slider 85 73 86 26% Two-Seam 47 59 97 13% Change 64 80 45 1% SOURCE: PITCHf/x Percentile among all pitches, with assumption that ride is good for the four-seamer, drop good for two-seamer, slider, and change. Changeup movement and velocity defined off of fastball.

In the pen, there’s a real focus on velocity and the fastball. Add in some command issues, and you could see why a team would push Ramirez towards throwing the four-seam more often. This, despite the fact that it had bottom-tier spin and movement.

In fact, that spin, and lack of ride, probably gave us a hint about what Ramirez “should” be doing with his fastball mix. Look at how his percentiles are all better across the board for the two-seamer. When a pitcher has a low-spin fastball, he won’t get the sort of ride and zip in the zone that can lead to whiffs and bad contact. But he can use that lack of spin to get good sink.

Voila, this year Ramirez has completely shifted over to the two-seam, to the point where you wonder if he’s throwing mostly two-seamers despite the fact that 14% are still registering as four-seamers. Look at how his four-seamer is getting some sideways wiggle now. In any case, he changed his fastball mix. And that’s not all.

JC Ramirez 2017 Pitch Mix Judged by Percentiles Pitch/Percentile Spin Horizontal Move Vertical Move Velocity % Used Four-Seam 7 75 6 96 14% Slider 77 59 92 41% Two-Seam 45 65 95 26% Curve 49 73 67 68 19% SOURCE: Baseball Prospectus Percentile among all pitches, with assumption that ride is good for the four-seamer, drop good for two-seamer, slider, and change. Changeup movement and velocity defined off of fastball.

He really embraced that low-spin fastball and made it sink for him. He stepped up his slider usage. In those two decisions, he threw his better pitches more often.

And then he added a new pitch that grades well across the board. Let’s check out his new curveball, which has above-average movement and velocity:

Ramirez still has flaws. His command issues haven’t gone away. If you look at his ability to hit within a baseball’s width of the edges of the strike zone minus his tendency to hit the middle of the strike zone (New Heart% – Edge% for his fastballs), he doesn’t grade well.

That lines up with our subjective reports of lack of command. But! With a 97 mph sinker that has good movement, perhaps the heart of the zone isn’t as scary a place. That’s helped Ramirez to the best strikeout minus walk rate (K-BB%) of his career at any level (minimum 10 innings thrown), along with those good whiff and strikeout numbers mentioned earlier.

Ramirez did add a new pitch, and that’s often part of the story when a pitcher is trying to prove he can be a starter and get through the lineup multiple times. But it looks like the emphasis on getting through the lineup multiple times also led to a change — from the four-seam to the sinker — that better took advantage of his natural abilities. That’s a fun, and rare, story.