So who am I talking about? If you guessed Octavio Dotel, you're WAY wrong. That dude throws his fastball over 80% of the time - one of the highest in the game, actually.
The answer is Carlos Villanueva, who's gotta have the most balanced four-pitch repertoire in baseball - at least in how he uses it, not necessarily based on effectiveness. Anyway, Villanueva throws his fastball 29% of the time and that's actually his most used pitch: he also features a change-up (26.6%), a slider (24%) and a curveball (20.4%). Talk about mixing and matching.
Carlos has always had a balanced repertoire, but it's become more balanced over time. In 2006, his rookie year, and 2007, he threw his fastball almost half the time, with the change-up his primary out pitch.. The next two years he took it down below 40% and mostly started using his slider more. Last year another 10% drop in fastball usage resulted in the curve getting up over 20%.
So, the natural question: is his stuff any good? Well, the short answer is it's hard to tell given the small sample size, him being a reliever, and being shuttled in and out of the rotation probably had some effect on how he used his pitches. But here's what the data says:
Except for during his rookie year, Villanueva's fastball has always been a below average pitch, and it was more than ever last year (-2.33 R/100 pitches), so good on him for recognizing this fact and gradually cutting down. His change-up and slider have almost always been above average. The curve has been up and down, but last year it was his best pitch (2.06 R/100), explaining its increased usage.
(By the way, the best off-speed pitches are usually worth about 3 R/100 above average - Marcum's change-up was 3.35 last year, second only to King Felix.)
Villanueva had an excellent xFIP of 3.39 last year, and from the data it seems like it may be partially explainable by Carlos' improved use of his repertoire (and mostly explainable by random reliever year-to-year variance, of course). I haven't studied pitch values enough to know if this kind of behaviour is sustainable on a year-to-year basis, but from what I can see in the number it looks like a pretty nice pick-up by AA.
(And yes, I know the trade is old news, but we've gotta talk about something in the dreary post-FA pre-ST wasteland.)
