Is Ubaldo Jimenez Back?

Over the last 30 days, this pitcher ranks second  in strikeout percentage among all starters with at least 20 innings pitched. In the second half of the season, this same pitcher ranks ninth among that group of starters in ERA, with a 1.94 mark. Since the beginning of June, the man in question has posted a 2.63 ERA. Of course, you know from the title that I’m talking about Ubaldo Jimenez.

But were you aware of how good he has actually been since a forgettable April in which he posted a 7.13 ERA? I wasn’t! In fact, he may have very well remained on free agency in many leagues even as his ERA continued to fall toward 4.00 and then below. All of a sudden, his season ERA stands at 3.62, he has struck out over a batter per inning, and memories of his first year and a half in Cleveland are fading.

Back in Colorado, Jimenez was your typical young, hard-throwing right-hander. He lit up the radar gun averaging between 95 and 96 mph with his fastball and kept hitters guessing with an assortment of three breaking and off-speed pitches. Though oddly he never recorded an impressive SwStk%, it was clear that the quality of his stuff was superb. One may have even been a bit disappointed by his strikeout rates, which were very good, but not exactly at the level you might expect if you watched him pitch.

Aside from the strikeout ability, he also induced his fair share of ground balls. This was key when calling Coors Field home as every pitcher knew that a fly ball had a pretty darn good chance of flying through that thin air and into the seats. But like many young hard throwers, control was an issue for Jimenez. He struggled to throw first pitch strikes and his walk rates hovered around the 10% mark.

But then something happened in 2011. His fastball velocity dropped nearly two miles per hour and his effectiveness declined along with it. He was then shipped off to the Indians to finish off a disappointing season. The following year, his velocity dipped another mile and a half per hour and he posted an ERA above 5.00. The downward spiral continued into 2013, as his velocity dropped even further and he allowed 19 runs over his first 4 starts.

While his fastball velocity is indeed up at the moment, that has only happened over his last four starts. That means that during his entire run, he was consistently averaging around 91 to 92 mph, and therefore a velocity rebound cannot explain his resurgence. Since his walk percentage remains poor, and his ground ball rate, although up from last year, is still below his peak, that leaves us with a spike in his strikeout rate. In fact, his current 23.6% mark is the second highest of his career, just below his 2010 mark of 23.9%. This is despite a fastball that comes in a whopping 4.4 mph slower on average.

The key may be a change in pitch mix. Here is how Jimenez has altered his mix since his velocity drop in 2011.

We see that acknowledging he has less muscle behind his fastball, he has thrown the pitch less frequently, essentially scrapped his curve ball and has significantly increased the usage of his slider. Interestingly, he has actually not induced a very impressive SwStk% on the pitch, but of his entire repertoire, he has thrown it inside the strike zone at the highest rate. He has also induced a ton of pop-ups with the pitch at nearly 26% of the time, while severely suppressing home runs on fly balls. The curve ball remains an effective pitch for him, so there’s no clear reason he has chosen to throw it less often, but given his velocity loss, it makes sense that he would sub the slider in for his fastball at times now.

He has also changed his mix a bit during this season. Check out the trend in the usage of both his slider and change-up.

During this season, he has increased his slider usage, while reducing his change-up usage. Again, his change-up results look pretty good, though he has suffered from an inflated HR/FB rate on the pitch. But, the slider has been a better strikeout pitch for him.

Sometimes it is said that when a pitcher loses velocity, he will need to endure one or more transition years before he reinvents himself and learns how to adjust his pitch selection to factor in diminished stuff. We may be seeing Ubaldo Jimenez doing exactly that. However, his control remains poor and his SwStk% sits below the league average, as he relies on getting an above league average rate of called strikes to rack up the strikeouts. So although I do think Jimenez has turned the corner, he still warrants caution in shallow mixed leagues.