The “Luck” Stats

A pitcher’s performance in any given season is something like 40% skill and 60% luck. That statement may sound extreme, but it’s the truth. So you can imagine just how much luck plays into a pitcher’s performance when we’re only halfway through the year, and just how much that might impact your fantasy team.

Luckily, The Hardball Times tracks a few very important “luck” statistics for pitchers, and we’re going to take a look today at which hurlers may be due for a downturn in their performance.

The first of these numbers is how many home runs a pitcher allows per outfield fly ball. My research in The Hardball Times Annual 2007 indicates that pitchers do have some control over HR/F, but not much. Most end up tightly clustered around an average of about 11%.

This early in the season, however, those numbers vary quite a bit. Let’s look at the five pitchers with the lowest HR/F in the major leagues:

Name              HR/F
Jake Peavy        1.2%
Brad Penny        2.4%
Chris Young       3.0%
Kelvim Escobar    4.9%
Tim Hudson        5.5%

You can tell that these numbers are unsustainable. PETCO Field does prevent fly balls from becoming home runs at a higher than average rate, but certainly it is not so extreme as to give hope that Peavy and Young will continue to avoid the gopher ball as they have.

Because home runs are so damaging, these are all guys who should expect to see large bumps in their ERAs (except, perhaps, for Hudson). If you can convince another owner that they will continue to pitch as well as they have, I suggest you sell now.

Another “luck” stat for pitchers is line drive rate. My article in the THT Annual found no year-to-year correlation in line drive percentage from one year to the next, which means that all pitchers allow around the same number of liners. What I did find, however, was that line drives were the worst type of batted ball to allow, as they drop for hits three-quarters of the time.

Who can we expect to allow a larger number of hits the rest of the way? Let’s have a look at the pitchers who have allowed the fewest number of line drives per batted ball:

Name               LD%
Paul Maholm        13.3%
Chad Durbin        13.9%
Joe Kennedy        14.2%
Fausto Carmona     14.2%
Daniel Cabrera     14.2%

In case you were thinking that my findings couldn’t be right, and that better pitchers generally allow fewer line drives, this list of leaders should show you that isn’t really the case.

Maholm, Carmona, and Kennedy have actually had some bad luck in other places to make up for the good karma they have received with line drives. But Durbin and Kennedy are due for a steep fall back to earth, and you should let go of them before that happens.

The third statistic we’re going to look at is left-on-base percentage. Unlike LD%, LOB% is far from being all about luck. Better pitchers generally leave a higher proportion of hitters on-base because it is harder to string together a series of hits or walks against them. (A couple good articles on LOB% can be found here and here.)

Nonetheless, LOB% is also a luck-intensive statistic, and it can pinpoint pitchers whose ERAs are about to soar. Let’s look at the leaders.

Name                LOB%
John Maine          83.8%
Rich Hill           83.3%
Johan Santana       82.1%
Dan Haren           81.8%
Brad Penny          81.2%

Brad Penny makes a second appearance in this article, which means that if you own him, you need to be selling now. Seriously, don’t even read this to the end, just go.

As you can see, we do have a pretty good list of pitchers here, but all of them are due to stumble somewhat, Maine and Haren (and Penny) especially.

Evaluating pitchers is a complex art, and sometimes all the luck that plays into their numbers makes it darn near impossible. But by looking more closely at their individual statistics, we can get an idea of which pitchers are playing in over their heads.

All of these statistics, and more, can be found in The Hardball Times statistics section.