With some trepidation, today we'll look at Bronson Arroyo. I'm scared, because Bronson's far less traditional than other pitchers. He throws a ton of pitches, varies his arm angle, pitches backwards, etc. I don't know if I'm up to the task of "scouting" him. But I'll try!
Pitches
Arroyo throws everything except the kitchen sink. He's definitely the kind of pitcher who will push MLB advanced media's pitch ID algorithms to their limits. But let's walk through this.
On the left (negative horizontal movement, in toward right-handers), you have four pitches. Near the bottom of the cloud you have Bronson's change-up (purple), and as you move clockwise you see his sinker (pink), and his four-seam fastball (red).
If you squint, amongst the four-seamers you should also see some pitches marked "FS" shown with dark-red (maroon?) triangles. That is Arroyo's split finger. It doesn't look distinct in this plot, but in the velocity plot below you can see that it is clearly well below the speed of his fastballs. This was the first I'd hear of him throwing that pitch, but Mike Fast (who remains my life-line when I'm doing this stuff) found a picture of him throwing it. So it's true, he has one. Mike also thinks that a good number of his splitters are misclassified as change-ups, so in all the pitch frequency/outcome stuff below please keep in mind that he may throw far more splitters than mlb gameday thinks.
Near the middle, you see his cut fastball (which doesn't break toward a RHB as much as other fastballs) as well as his slider. The slider may well be a variant on his curveball, or may be a completely separate pitch. Reports from Arroyo himself vary. It looks like a normal slider via pitchf/x, though, so I'll treat it as such (though I do think some cutters may be misclassified as sliders, or vice versa--whatever!).
Finally, there are the curveballs (including one curve ball obviously misclassified as a change-up). Arroyo throws these from his normal arm angle, and will also drop down and sweep them across the plate. He also seems to drop down occasionally when throwing his sinker, slider, and fastball:
(the lower cloud shows those times when he drops down).
Velocity
Arroyo is not a hard thrower, only occasionally topping 90 mph. His fastballs all seem to be thrown in the upper-80's, while you can see that his change-ups and split fingers (and sliders) seem to all come in at around 80 mph (note also how distinct the spitters are in this plot compared to the fastballs). His curve ball is slow and loopy, sometimes leaving his hand in the upper 60's, but averaging in the low 70's.
Outcomes
| Pitch | Use% | Strike% | GB% | Whiff% | LgWhiff% |
| Four Seamer | 18% | 63% | 30% | 6% | 6% |
| Two Seamer | 23% | 63% | 57% | 5% | 5% |
| Cutter | 4% | 60% | 58% | 9% | 8% |
| Slider | 3% | 71% | 36% | 8% | 14% |
| Change-Up | 25% | 69% | 49% | 7% | 13% |
| Splitter | 3% | 68% | 9% | 3% | 16% |
| Curve | 25% | 68% | 28% | 10% | 12% |
Overall, we see Arroyo throwing about a quarter each of four & two seam fastballs, change-ups, and curves. Many of the change-ups may be splitters, but they are pretty similar in function. He throws his offspeed stuff for strikes more often than his fastballs--I'd guess that the reason is that he intentionally throws his fastballs out of the zone at times, rather than him just having superior control over the junk.
In terms of effectiveness, his two-seamer seems surprisingly effective at inducing ground balls. I didn't expect much as I think of him as a fly ball pitcher, but he's had his GB% in the 43-45% range the last two years. He also gets a decent rate of grounders from his cutter and change-up. But his four-seamer and curve are fly ball city. It'd be interesting to see if he favors them less when pitching at GABP than elsewhere.
While Bronson can get the ball over the plate, and has some tools to keep the ball on the ground, he does not have a lot of strikeout pitches. His cutter seems a bit above average (in small sample size), but all other pitches get whiff rates that are below league average. The curve, in particular, surprised me, as that's the pitch I think of as being his out pitch. Then again, his strikeout rate has been in the 5 k/9 range over the last two years, so...
Approach
| vs. RHB | Opening Pitch | Two Strikes | Full Count | Behind |
| Four Seamer | 23% | 22% | 19% | 13% |
| Two Seamer | 21% | 20% | 11% | |
| Cutter | 1% | 4% | ||
| Slider | 6% | 4% | 1% | |
| Change-Up | 18% | 7% | 34% | 6% |
| Splitter | 5% | 1% | 1% | 25% |
| Curve | 24% | 43% | 33% | 31% |
Against righties, Arroyo seems to debut with pitch selections that seem pretty similar to his overall choices. There is a big change when he's ahead and has two strikes on a batter though: he starts throwing his curve ball almost twice as often. As noted above, that is his out pitch, even if it does not have an above-average swing-and-miss rate.
With a full count, Arroyo starts throwing lots of change-ups, in addition to continued heavy use of his curve. Some of his other pitches that may be more "show" pitches, like the cutter and slider, seem to be put aside. I love the last column, however: with a 3-0 count, most pitchers throw almost exclusively fastballs. That's what we saw from Volquez and Cueto last year. But Arroyo isn't like that. Instead, he throws almost entirely curve balls and splitters. But he can get them all over the plate...so why not?
| vs. LHB | Opening Pitch | Two Strikes | Full Count | Behind |
| Four Seamer | 20% | 38% | 10% | 19% |
| Two Seamer | 29% | 34% | 25% | 5% |
| Cutter | 3% | 6% | ||
| Slider | 0% | 2% | 1% | 5% |
| Change-Up | 17% | 15% | 40% | 62% |
| Splitter | 3% | 1% | 1% | 5% |
| Curve | 27% | 6% | 23% | 5% |
Against lefties, the main difference is that with two strikes, Arroyo largely abandons the curve ball and focuses instead on fallballs and, to some degree, his change-up. Arroyo will still use his curve against lefties--just not when he's trying to strike them out. Once again, the Behind column is fascinating: Arroyo throws his change-up 62% of the time in 3-0 counts against left-handers! That's awesome.
Conclusion
If there's ever been a crafty righty, it's Arroyo. He is a prototype of someone who pitches backwards, throwing breaking balls when behind and fastballs when ahead. And perhaps this is the reason that he's been able to beat his peripherals by roughly a half-run per inning over his career with the Reds. Whether he'll be able to carry it forward this year...who knows? He's a pretty unique pitcher. I don't see any reason why he can't continue to have success.