Going into the 2013 season, the bullpen was seen as an area of strength for the Chicago White Sox. After all, the relief corps was a bright spot for them in 2012, and they added veteran Matt Lindstrom via free agency.
Unfortunately, the results this season are a mixed bag for the White Sox.
According to Baseball-Reference.com, for example, the New York Yankees (91.0 percent) and Texas Rangers (89.5) are the only AL teams with a higher save percentage than the White Sox (81.0), yet ESPN.com notes that the group’s 3.88 ERA is in the league’s lower half.
They are outstanding in one statistical category, but middling in another. Why?
As we look at the root causes for the bullpen's uneven performance, there are three areas of particular concern.
To start, the bullpen has to improve on its inherited runners scored (IRS) percentage.
So far this season, the relievers have inherited 81 runners, while allowing 25 of them to score. The resulting percentage (30.9) is below the AL average (32.3), but far too high for a team that covets runs like the White Sox.
The most egregious offender has been Jesse Crain. Although he leads the league in appearances with 26 and has an exceptional 0.78 ERA going into Monday’s game against the Chicago Cubs, he has allowed an astonishing 41.6 percent of inherited runners to cross home plate.
Also concerning are Lindstrom and Nate Jones. Their IRS percentages check in at 33.0 and 31.3, respectively.
There are a couple of bright spots. Matt Thornton is third in the AL among qualified relievers with a 7.1 IRS percentage, per NBCSports.com, and Hector Santiago has yet to allow an inherited runner to score. Unfortunately, the bulk of the opportunities have fallen to Crain, Jones and Lindstrom, and they have struggled at times.
One of the results of allowing that many men already on base to score is that leads are hard to hold. In 59 save situations (not opportunities), the White Sox have only held the lead 36 times, which breaks down to a 39.0 percent failure rate.
To be sure, that is much lower than a team like the Baltimore Orioles, who have failed to hold the lead 55.8 percent of the time, but it's still too high for a team that covets runs.
Finally, the bullpen is walking batters at an extraordinary rate. According to ESPN.com, the 71 base on balls the relievers have issued as a unit ranks third worst in the AL, and their 1.69 K/BB ratio is last in the league.
Now, in an effort to rationalize these numbers, several mitigating factors must be mentioned.
First off, the White Sox bullpen has—by a wide margin—been thrust into the most high-leverage situations in the AL. According to Baseball Prospectus, those are defined as having "more importance” to the outcome of a game.
For the year, the White Sox have an average leverage of 1.149 in relief appearances. To put that number into it's proper context, the league average is .986. In essence, the bullpen has been called upon in critical situations more often than the rest of the league.
Additionally, they have used the same reliever on consecutive days 33 times, which leads the AL.
Thanks to individual struggles—Donnie Veal—and injuries to the starting rotation—John Danks and Gavin Floyd—White Sox manager Robin Ventura has been forced to lean heavily on just a few relievers.
That has often put them in untenable situations.
The White Sox's .981 fielding percentage is not doing them any favors, either. The have committed the second-most errors (33) in the AL, which has led to 18 unearned runs.
Finally, the offense needs to perform better with runners in scoring position. The White Sox are ahead of only the Seattle Mariners with a .225 team batting average with RISP, and the 115 runs they have scored in those situations is good for last in the AL, per ESPN.com.
There is no question that more runs would make the relievers' job that much easier. They cannot count on a dramatic increase in run support, however.
See, the bullpen cannot control the offense, nor the types of situations it comes into the game facing.
If the relievers can cut down on the walks and improve their IRS percentages, though, their overall performance will dramatically improve, and a division title may well be within their grasp.
All advanced statistics are from prior to the game Monday night and are courtesy of Baseball-Reference.com unless otherwise noted.