Midterm report: Tigers bullpen is their biggest weakness

The Tigers bullpen was blamed for letting a championship slip away in 2013. That came on the heels of a season where they went into the playoffs without a closer. Then, they lost their three most trusted relievers from that group. Joaquin Benoit left as a free agent. Drew Smyly was moved to the rotation to take the place of Doug Fister, who was traded. The club declined to pick up the option on Jose Veras, who worked in a set up role after being acquired at the trade deadline.

The attempted fix was to sign Joe Nathan as the closer, Joba Chamberlain as a set up man, and acquire Ian Krol in the Fister trade. The rest was pretty much status quo. Bruce Rondon was counted on- again- for some late inning work. Phil Coke was extended for another season. Al Alburquerque would be back, hoping to reduce his lofty walk rate, and home run ratio.

In a nutshell, it hasn't worked. Mainly, Nathan hasn't worked, but also pretty much anyone not named Joba has failed to get the job done.

Here are the numbers, comparing the Tiger bullpen of 2014 with the 2013 crew and with the other bullpens in the American League.

Bullpen

You know the bullpen narrative according to Tigerdog: As a whole it has been below league average every year since 2006, yet the team manages to maintain a save percentage among the best in the league every season when they are in contention. This year is no different, despite the woes of Joe Nathan and company.

The Tigers' relief corps ranked 12th of 15 American League teams in ERA last year, and they rank the same this season. Nothing remarkably different stands out in the ratios. They are still fairly mediocre as a group, with a save percentage that is actually ahead of last year's pace. Comparatively, they haven't let many leads slip away after the sixth inning.

Does this mean that all is well? Hardly. Here is a look at the individual performances and how they rank among their peers in the league.

What we see in the numbers here is that the Tigers have a collection of replacement-level relief pitchers so far this season, with only Chamberlain providing any significant value. He ranks 16th in the league in WAR and 13th in FIP (minimum 20 IP). No other Tiger reliever cracks the top 50 on that list. The Tigers have talented arms, as every team does. What they don't have is relief pitchers who are consistent.

Relief pitching is a crap shoot. A team can spend a lot of money for a "proven closer" who suddenly loses it, or they could spend almost nothing on their bullpen and find relief pitchers in their minor league system who come up and are lights out, until they burn out. Relievers with a good track record are expensive in July, and will cost a couple of prospects, even for a rental. But not having a reliable bullpen can lead to- what it led to in Boston last October.

A lot depends upon Nathan, and whether he can become a reliable closer once again.  If not, they need to find one. In fact, they may want to buy some insurance, lest we see a repeat of 2012 when Jose Valverde picked the worst possible time to lose it completely. Even if Nathan pulls it together, they could use a few good men for late inning duty.