Red Sox lefty Eduardo Rodriguez was called up in May of 2015 for a spot start, but he looked so good in that start that he ended up as a regular in the rotation. For a 22-year-old rookie, he performed very well in 2015, putting up a 3.85 ERA (112 ERA+), 1.290 WHIP, and a 10-6 won-lost record, and there was much excitement about his potential. Unfortunately, his performance in 2016 dampened much of the buzz. He ended his age 23 season with a 4.71 ERA (97 ERA+), 4.43 FIP, 1.299 WHIP, and a 3-7 record. He started the season on the disabled list with a right knee patellar subluxation, not pitching his first game until the end of May, and was demoted to the minors by the end of June, sporting a 8.59 ERA (1.75 WHIP). When he returned to the big leagues in mid-July, he pitched much better through the end of the year (3.25 ERA, 1.14 WHIP), but there remains some uncertainty about his role with the major-league club in 2017 once David Price returns from the DL.
What he throws. Rodriguez is still tinkering with his repertoire, as might be expected for a pitcher his age. His constants are a four-seam fastball (“FF”) and a changeup (“CH”). In 2015, and perhaps in 2016, he had issues with tipping his slider (“SL”), but it’s still one of his more common pitches. In 2016, he added a curve (“CU”) to his repertoire – though it’s more like a slower slider than a true curve – and he also experimented with a cutter (“FC”) early in the season:
Pitch usage and trends: Rodriguez used his new curve almost entirely against right-handed batters, throwing a total of four curves to lefties over the season. Left-handed batters saw more sliders and fewer changeups. When behind in the count, he tended to avoid his slider, using his changeup instead. His cutter was used so rarely (0.8% of his pitches) that it doesn’t mean much, but he used it more against RHB (0.9% of pitches) than lefties (0.5%):
He changed his pitch usage significantly as the season progressed. (In the charts below, his minor-league stint is indicated by the vertical blue line.) To start the season, Rodriguez hardly used his slider at all, focusing on his fastball and changeup. He also tried throwing cutters in a couple of early games before abandoning the experiment for the season. After returning to the majors in July, he threw his slider much more consistently for a month or so before apparently gradually losing faith in the pitch and becoming once again mainly a fastball/changeup pitcher:
Pitch value. In 2016, most of Rodriguez’s pitches were just about average in effectiveness. His fastball was fairly good against left-handed batters, but average against right-handed batters. His slider was slightly worse than average, based both on total bases per 100 pitches and on balls per 100 pitches. His changeup was also a little worse than average. Left-handed batters didn’t get quite as many total bases off it as righties, but they got far more balls. The curve looks like his only strongly positive pitch, at least to righties. (Recall that he only threw four to lefties: One of those four was a single, leading to a small-sample-size value of 25 total bases per 100 pitches.)
Pitch location: At the beginning of his 2016 season, Rodriguez was quoted as planning to “just be the same aggressive guy, attack always in the strike zone with a changeup, a curveball now, with a cutter and heater.” However, many of his pitches tended to fall outside the strike zone. His slider to right-handed batters, and his changeup to LHB, both were likely to be outside the zone down and in, while his curve and changeup to RHB tended to be just outside. Although his walk numbers in 2016 were mediocre rather than terrible (3.4 BB/9 in 2016), they were a step back from 2015 (2.7 BB/9) and suggest that a more aggressive approach to throwing strikes may help him: