Deconstructing His Ubaldoness

What in the name of Bob Gibson, 1968, is Ubaldo Jimenez up to? Two months into the season, he has already amassed a 13-1 record and a 1.15 ERA. In fact, it's even better than that, because his RA (which neglects the largely irrelevant distinction of unearned runs) is the same other-worldly 1.15.

Is UJ really this good? Can he maintain this pace?

It's worth noting that Jimenez is no flash in the pan. He has been considered a prime cut since his signing out of the Dominican at age 16, and has posted a solid first four seasons of work, sporting an ERA around 3.70 and nearly eight strikeouts per nine IP. He's big, coachable and fires mid-90s darts. Scouts have always felt that his control and health were the only things standing between him and stardom.

That said, 13-1, 1.15 with Coors as home base is pretty special. Below-average major league starters sometimes shut down their opponents for two or three turns, but rarely this well, this long. Usually, exploding out of the starting blocks like this takes a combination of skill, luck and good teammates. And Jimenez is no exception.

Ubaldo is responsible for a goodly portion of his results. First, he's averaged more than seven innings a start. That's both a cause of good outcomes and a result. As the best pitcher whom opponents are going to see in a given game, Jimenez helps himself by remaining effective as long as possible into the start and minimizing the use of relievers.

Second, he's fanned 88 batters in 101 innings, which is about his career rate, but he's shaved a walk per nine off his career average. He's surrendered just three taters all year, and six hits per nine, which are both superb, and about half his former rate. But as we shall see, we now have the tools to see that both those figures are a tad misleading.

MLB now records the location, velocity and horizontal and vertical break on every single pitch, and their result. With that information, researchers have been able to tease out correlations that suggest when results are whacky. For example, we know that pitchers have little control over the batting average on balls in play (BABIP) against them. So when we see batters scuffling at .235 on balls in play against Ubaldo, we know that he's got a bill coming due. (Average BABIP in the NL is .298. Some pitchers can sustain a BABIP down around .280, but not much lower.)

We can break BABIP down much more granularly to see how exactly Jimenez has been surfing a wave of serendipity. Although Jimenez serves up line drives about as often as everyone else, the batting average against him on those balls is .600, compared to a league average of .722. So before congratulating him on keeping guys off the bases, he should be offering obeisance to the Patron Saint of Right At Someone. The same for ground balls, which reached the outfield at an 11% rate, a mere shadow of the league rate of 17%. That could be the result of a Rockie infield slick with the leather, which appears to be a fact, but not sufficient to reduce the hit rate on worm-killers by 64%.

It breaks down further. Those three meager home runs? They smack of a visit to Flukeytown. Batters have poked just 5.8% of their fly balls off Jimenez into the stands, about half the normal rate. This is possible if those sky-balls present as pop-ups, but Ubaldo has no particular pop-up proclivities.

There's more. Hitting with runners in scoring position is often cited as a key to run scoring. It's largely a matter of luck that tends to regress to mean for a player, team or pitcher over time. Ubaldo is surrendering just a .186 BABIP with runners on base. It's certainly possible that he bears down more, digs deeper and makes his best pitches when the enemy threatens, but that would show up in strikeouts and walks, not BABIP. Fortune tends not to smile so broadly as .186 BABIPs for whole seasons.

Finally, you may have noticed that Jimenez has 14 decisions in 14 starts. That's unusual for a pitcher who's left 25 innings for his relief corps to handle. But handle they have, watching carefully over those 1-0 leads he's left to them. The bullpen trio of Joe Beimel, Matt Belisle and Manny Corpas are all in the top 20 of reliever effectiveness.

Given all that, how great has Ubaldo Jimenez actually pitched? Baseball Prospectus has created a new yardstick that strips out luck, ballpark and defensive efficiency and measures what a pitcher's ERA would be, all things being equal. In other words, given a pitcher who walks and strikes out at his rate, and who induces grounders, flies and line drives at his rate, what should Ubaldo Jimenez's ERA be? (BP calls this SIERA, for "Skill-Interactive ERA.")  Their analysis suggests that Jimenez has been the 16th best pitcher in MLB with a SIERA of 3.43.

Before you scoff at the difference, remember that a 3.43 ERA is pretty sweet. Based on BP's analysis, 20 more starts at a 3.43 ERA would leave Jimenez with a 2.49 ERA for the year and somewhere between 20 and 22 wins. On the other hand, it's hardly historical, or even the best in the league. It suggests, as does all the information above, that Jimenez is a top 20 hurler on a top five run of luck.

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