How bad -- or good -- is the Tigers bullpen?

One-third of the 2014 baseball season will be in the books when the Tigers play their 54th game against the Toronto Blue Jays Tuesday. I figured Monday’s off day would be a good time to look at where the Tigers bullpen ranks among the competition in the American League, and in what areas it could use some improvement.

While reviewing the Tigers bullpen in recent seasons, it has been apparent that the team’s relief corps doesn’t put up very good numbers as a group. In fact, the Tigers have had a bullpen ERA higher than the league average, ranking no better than 10th among AL teams, in every season since 2006. In 2013, they ranked 12th with a 4.01 bullpen ERA.

However, the Tigers have managed to do very well in the late innings when they have a lead, in most seasons. The Tigers bullpen has had a save percentage -- holding leads of three runs or fewer from the seventh inning or later -- above 70 percent in each of the past four seasons. In fact, the save percentage for the season was 71 percent in 2010, 2012, and 2013, ranking fifth, seventh, and fourth in the league. The Tigers had a league-leading 84 percent save rate in 2011. As we know, the team won their division and went on to the ALCS in each of the past three seasons.

Go back one season to 2009, and the save percentage of just 64 percent stands out as one big reason why the team didn’t clinch its division, as the Tigers allowed more than one-third of their late-inning leads to slip away.

Well, the 2014 Tigers bullpen is true to form. Tigers relief pitchers rank 13th in the league with an ERA of 4.44, but it ranks fifth in the league with a save rate of 70 percent.

Of course, bullpen ERA and save percentage aren’t everything, but I believe there is something to be learned by looking at these numbers. While ERA can be misleading for individual relievers, bullpen ERA is about as useful as ERA for starting pitchers, since the bullpen as a whole may inherit base runners, but take responsibility for every hitter thereafter. The reverse is true for starting pitchers.

In the case of save percentage, save opportunities represent the highest leverage situations that a team’s pitching staff will see over the course of a season. Convert those saves, and every one of them goes in the win column. Blown saves don’t necessarily result in a loss, as Joe Nathan can attest to, and a team can certainly win games without registering a save, but it’s those close games in the late innings where relief pitchers earn their pay.

One thing jumps off the charts at you when looking at these rankings. While the Tigers are 13th in the league in bullpen ERA, but second in save percentage, the Oakland A’s are just the opposite. Oakland leads the league in team ERA, is second in bullpen ERA, but is dead last with only 50 percent so far this season. The A’s, however, have easily the biggest positive run differential, so many of their wins are coming by large margins.

Other statistics show the Tigers bullpen overall to be closer to league average.

Rankings are from best to worst. Statistics through games of May 31.

Here, we see that the Tigers’ relief corps is in the middle of the pack in FIP and strikeout rate. They’re among the best in walk rate, but have had an issue with the home run ball. The difference between ERA and FIP could indicate either bad luck or bad defense.

Now, a look at the individual performances of relievers currently manning the Tigers bullpen.

-- The Tigers have a total of six blown saves. Four of those belong to Nathan, and two of those blown saves resulted in a loss. The others were blown by Joba Chamberlain against the Twins, and Ian Krol, who gave up a grand slam to the White Sox. The home run ball has been the big culprit in the blown saves.

-- Nathan’s four blown saves are the second highest in the league. Two came in the first week of the season, and he managed to get a vulture win in those. The other two have come on the most recent road trip, and resulted in losses. He ranks fourth in the league with 13 saves.

If we can Porcellitize Nathan, from April 12 through May 19, the Tigers' closer gave up just one run in 13 appearances, and had an ERA of 0.69 with one strikeout per inning. His issue has been the home run ball. Nine of the 12 runs allowed by Nathan have come on home runs. In fact, if you take away those four home runs, the bullpen's ERA would be 3.80, right in line with the league.

-- Chamberlain has been everything that Dave Dombrowski had hoped for when he signed the former Yankee to a one-year bargain contract last winter. After giving up three runs in his first two games as a Tiger, he has allowed no runs in 21 of 24 appearances, posting an ERA of 1.69 with an identical FIP and a WHIP of 1.13. He has not allowed a home run, and has a ground ball rate of 53 percent, with a strikeout rate of 10.55 per nine innings.

-- Al Alburquerque has an ERA of 1.59 and a WHIP of just 0.88 in 11⅓ innings since May 4. The key to his return to success has been a sharp drop in his BB rate, which has been cut nearly in half. He has allowed three home runs, which were his Achilles heel last year, combined with the league's highest BB rate among qualified relievers.

Al Al has been throwing his nasty slider 70 percent of the time, and has brought the batting average against that pitch down from .300 in April, to just .231 for the season by now. He is currently on a run of six scoreless appearances. He has made more appearances than any other Tigers pitcher with 22.

-- Ian Krol is the Tigers only reliable left handed reliever. Krol has been somewhat fortunate in that he has an ERA of 2.41 but an FIP double that number, at 4.82. His Achilles heel has been the home run ball. He has held left-handers to a .229 average with a .400 slugging percentage, while right-handers have hit .289 with a .325 slugging against him. Krol has given up less than two walks per nine innings. He has allowed 35 percent of inherited runners to score, three of those coming on the infamous grand slam against the White Sox in his lone blown save.

-- Evan Reed has posted some serviceable numbers, with a 3.92 ERA, 3.88 FIP, and 1.31 WHIP. He holds the highest ground ball rate in the Tigers bullpen at 56.5 percent. He doesn’t walk many, has allowed two home runs, but gives up some fairly solid contact at times. He is a decent middle reliever, but should be used sparingly in high leverage situations.

-- Justin Miller is the low man on the pole, at least among the right-handers, being up and down from the minors this season. In slightly more than 10 innings, Miller actually has the best walk rate on the team, while allowing just one home run. He strikes out just 4.35 batters per nine innings, and doesn’t get a lot of ground balls. He looks like a serviceable middle reliever with a 3.48 ERA, 3.63 FIP, and an 0.97 WHIP. If he can maintain those numbers with more work, he’ll be just fine.

-- Other pitchers: Luke Putkonen, Jose Ortega, and Corey Knebel have allowed a total of 15 runs in seven innings. Take those three out of the equation, and the bullpen ERA drops to 3.61, which would rank fifth in the league. Unfortunately, that's not how it works, but there is the possibility of such performance going forward. Drew Smyly did throw seven innings of flawless relief, but he is in the rotation.

Here are some other trends and tidbits that I’ve noticed in the numbers:

-- There is one very encouraging trend. In the month of May, the Tigers bullpen posted an overall ERA of 3.62, with an FIP of 3.67. The WHIP was a more respectable 1.29.

-- In May, the Tigers bullpen improved that HR/9 rate from 1.28 in April to 0.79 in May.

-- On the other hand, the Tigers had the second lowest bullpen BB/9 rate at just 2.94 in April, which rose a bit to 3.18 in May. Walks are clearly not the issue, here.

-- For all the concern about getting the ball to the eighth inning, the Tigers have not blown a lead in the seventh inning all season. The relievers that typically make us most nervous have held every lead that they’ve been given to hold.

So, what’s wrong with this picture? Not much, really. As long as they all remain healthy, and Nathan can get back in the groove that he was in between his dead arm phase and his melt down phase, the Tigers bullpen should be just fine.

Oh -- Phil Coke? Well, what can you say about him that hasn’t already been said? Nine lives? Check. Stinks? Check. Should be optioned? Yep. Needs to be released? Done that. Is okay as long as he’s never used in a close game? Okay, we’ll go with that one for today’s purposes.