It’s no question Ubaldo Jimenez is having a terrific season this year. First it was the no-hitter against the Atlanta Braves (first time ever for a Rockies pitcher), then it was the .78 ERA after 11 starts, being named NL starting pitcher for the All-Star game, and garning some serious Cy Young consideration among the voters (15 wins and 2 losses!). But Ubaldo hasn’t been Ubaldo lately. In fact, it seems like he has had two different seasons. Here is a table showing his pitching line for the first eleven starts and last nine starts.
What a difference! His ERA exploded to over five and a half while his BABIP has regressed to right around the MLB average. He’s also not getting as deep into games, pitching over a whole inning less per start. Interesting enough, his strikeouts have gone up just slightly while his walk and home run rates have gone up (bad) considerably more.
So the question is now, what’s up?
Of course, there has to be some regression going on here. His ERA and BABIP can’t be that good all season long. But he hasn’t been pitching the same as evident in his increased walk and home run rates. So, what’s up?
I choose to split his season after his eleven starts, because that is where it seemed like he started to regress. So I decided to check out the pitch f/x data from MLBAM to find out if there was any notable differences between the two splits.
The first stat I noticed was his wOBA on contact, which was very low in his first eleven starts. I checked the data and it turns out he had the lowest wOBAc in the Majors for that same time period. That is not the case right now as his season’s average rose to .305, ninth among the starting pitches. The batted ball rates seem to now favor a higher BABIP and home run rate while Ubaldo isn’t attacking the zone as much as he was earlier in the season. So did Ubaldo changed his pitch selection? The following table shows his pitch usage by batter handedness for the season split.
For more on Ubaldo’s pitches, read this previous article.
Marginal changes here. If there was a major difference, it would be the increased number of fastballs to left-handed hitters. Other than that, Jimenez didn’t change much how he approaches hitters.
Digging deeper into his specific pitch types, here are the run values per 100 pitches and the zone percentage.
|Pitch||1st 11||Last 9||1st 11||Last 9|
I expected that his run values would worsen (lower is better here) for most of his pitches with the slider being the exception. I checked the location of his slider but it didn’t seem like it changed much during the splits even if he threw it in the zone less later in the season. But how many or whichever stats one could look, Ubaldo has been hit harder as of late while not helping his cause by walking more batters.
Somehow regression happens in baseball. Very few players can keep up with a highly exceptional season like a sub 1.00 ERA. It just doesn’t happen. After his worst start of the season lat Saturday, people in the baseball world are taking note of this are asking the question I’m asking. Why?
Apparently some have questioned whether it was cause by physical fatigue, but manager Jim Tracy disagrees. I going on the same boat with Tracy. This man has already pitched two full seasons in his career and his fastball velocity has stayed up. He is not in uncharted territory and his arm seems healthy. Every indication just points towards regression.
Stats and data form Baseball-Reference, Fan Graphs, and MLBAM