Note: I don’t like to put up transaction analyses before deal terms are known, so I’m going to focus on Perez himself. Since I’ll be travelling over the next few days, I won’t have a chance to put this post up later.

Last year, Brandon League had the second worst FIP in among relief pitchers with at least 50 innings pitched. The Dodgers apparently want the only pitch who was worse, as Dylan Hernandez is reporting that they close to signing Chris Perez to a one-year deal. Though Perez (9.0 K/9, 3.5 BB/9, 1.8 HR/9) took a much different path to his awful FIP than League did (4.6 K/9, 2.5 BB/9, 1.3 HR/9), each pitcher was worth approximately -1 fWAR in relief last season. Perez also had some significant (but kind of funny) off-field issues last year, but that’s not what I’m concerned with on this blog.

So, why was Perez so awful last season?

1. He was injured

Perez spent about a month on the disabled list last season with right (throwing) shoulder tendonitis. It’s possible that this impacted his results, since he had a few bad outings in a row before landing on the DL. This also means that the physical, which still needs to happen, is not a formality.

2. He didn’t throw as hard

Below is a chart of Perez’ pitch velocity from Brooks:


Overall, Perez’ fastball averaged 93.5 MPH in 2013, and 94.7 MPH in 2012, a drop of around 1.2 MPH. However, September was Perez’ worst month despite his fastball velocity being closer to normal. In 9-1/3 innings in September, Perez allowed 10 runs and batters had a .400/.490/.814 line against him.

3. He allowed harder contact

One of Perez’ main skills before last year was his ability to limit hits on balls in play. His career BABIP allowed is .256. Last year he allowed a BABIP of .294, a career high. This fluctuation wasn’t just bad luck:


Perez allowed an overall LD rate of 25.93%, per Brooks’ data. This is a career high by a significant margin; his second highest was 22.94% in 2010, his only other season above 20%.

4. Dingers!

Perez had a severe home run problem in 2013. He allowed 11 homers in 54 innings pitched last season. The move from Cleveland to LA won’t help him much, since the stadiums have similar home run park factors.

A regression in Perez’ HR/FB ratio could potentially help him next season. In 2013, Perez allowed a HR/FB rate of 20.0%. This was the highest by any relief pitcher with at least 50 innings pitched (Brandon League was second, with 19.0%). The statistic xFIP uses FIP and normalizes a pitcher to a league average HR/FB ratio, which is usually around 10%. Chris Perez’ xFIP last season was 3.83, about 1.2 runs below his FIP. His xFIP- was 97, slightly better than league average.

However, there’s evidence that this HR/FB ratio wasn’t just a fluke. From 2008-2012, Perez’ HR/FB ratio was 8.33%. Per Baseball Heat Maps, Perez’ average batted ball distance on fly balls and home runs in 2008-2012 was 277.9 feet. In 2013, the average distance jumped to 301.0 feet. There are some small sample caveats with one season of data, but on the surface a higher HR/FB ratio does make sense.

5. He wasn’t very good in the first place

Perez seems like a stereotypical “Proven Closer” guy. He’s had an up-and-down career, but his career FIP- is 102 and his career xFIP- is 100. That means that his peripherals are league average over the last six seasons. His best single-seaso FIP- is 84, which is decent. However, he’s only had two seasons with FIP-s below league average. In 2011, he had 36 saves despite a FIP- of 109 and XFIP- of 124.

To be fair, Perez’ ERA- is a bit better (85 career), but I don’t like using ERA to analyze relievers.

In my opinion, the Chris Perez signing has very high risk and limited upside. It doesn’t make much sense to me to add another reliever who just had a Brandon League-esque year, even if it’s only on a one year deal. Essentially, Perez can be viewed as a replacement for Ronald Belisario in the bullpen. Belisario has been erratic at best, but he’s never had a year as bad as Perez’ 2013. If I had to pick between the two, I would have stuck with Belisario.

With this signing, the 2014 bullpen is likely finalized, and looks like this:


I’m okay with having Jose Dominguez et al start in the minors, but Perez seems like an especially risky way to replace them. Along with the way that Paco Rodriguez finished the season, Chris Withrow‘s peripherals, Brian Wilson‘s health, and the fact that Brandon League still exists, the bullpen is filled with players that have the potential to not pan out in 2014. Bullpens are historically volatile, but Don Mattingly will need to watch this group closely.