The Red Sox and Pirates officially completed a trade that was more or less done a few days before Christmas. Joel Hanrahan goes to Boston, either as the closer or insurance for oft-injured closer Andrew Bailey, and several players often characterized as spare parts go to the Pirates. One of those spare parts, Mark Melancon, happens to be the bullpen arm that Hanrahan more or less directly replaces on the Red Sox roster.
The idea is that Hanrahan upgrades Boston's bullpen. It is debatable if he actually will though. The fact that this trade happened suggests a team with a surplus of successful bullpens, like the Mariners may have at the trade deadline, could swing some interesting trades.
On the surface there appears to be no room for a debate between Hanrahan and Melancon. Hanrahan was an All-Star in 2012; Melancon got demoted to AAA a few weeks into the season because he performed so poorly. Melancon got called up again and pitched mostly in middle relief, finishing with a 6.20 ERA and 1 save in 41 appearances. Hanrahan had a 2.72 ERA and 36 saves in 63 appearances.
Mark Melancon is an extreme example of when relief goes horribly wrong. It usually takes more than poor pitching to maintain an ERA over 6.00 with enough talent to stay on a roster. Melancon is no exception. He stranded only 59.4% of baserunners last year, way down from the 75.6% rate he stranded them in 2011 when he posted a commendable 2.78 ERA. This goes a long way towards explaining how Melancon's ERA more than doubled even though his WHIP only rose from 1.22 to 1.27 between the two seasons.
It is tempting to say that Melancon just had some tough luck in 2012 (and maybe some good luck too in 2011), but I don't think that's quite right. Melancon gave up 8 home runs in 2012, good for a whopping 22.2% HR/FB rate. Literally, almost 1 in 4 fly balls hit off of Melancon flew over the fence. Melancon also posted the lowest walk rate of his career in 2012, which suggests to me that he might have been too aggressive in the strike zone. Still, I wonder how many hitters over the course of a season hit 1 out of every 4 fly balls out of the yard in batting practice, much less a competitive game. The home runs explain some of Melancon's inability to strand runners; it is remarkably difficult to stop runners when they are allowed to freely trot around the bases.
Meanwhile, Hanrahan is the ying to Melancon's yang. He was a classic "heart attack" closer (as I like to call them). Hanrahan is tough to hit off of, partly because he misses the strike zone as much as he misses bats. His K/9 and BB/9 rates appear joined at the hip. They rise and fall together. Not surprisingly, Hanrahan had tons of walks with all his strikeouts last season, but surprisingly he stranded a staggering 89.7% of baserunners. There were plenty of baserunners on when Hanrahan came in; they simply didn't cross home plate.
Where there are baserunners there is risk. Melancon and Hanrahan both had identical 1.27 WHIPs last year, meaning they both allowed as many baserunners when they pitched. However, one of them gave up runs over twice as often as the other. Some of the variation can be explained by pitching ability and approach, but most of it is the way the balls bounced for these two pitchers. Most pitching skill is wrapped up in getting outs, and pitchers that are better at getting outs also prevent batters from reaching base in the first place. The extreme results both Melancon and Hanrahan got with runners on helped foster a market where one is superior enough to replace the other - even though they both generated outs at the same rate last season.
There isn't much stopping Melancon and Hanrahan flip-flopping success stories next year, which is the point. Melancon's home run rate would have cut in half with only 4 fewer home runs allowed - less than one a month. For comparison, a similar drop for a starting pitcher might take something closer to one a week. The Pirates might have just made a neutral move talent-wise while getting a younger, cheaper arm with more team-controlled years.* However, statistics carry weight in the trade market. Teams still value players who have produced in critical roles over ones who might have as good of odds to produce in a similar role.
*If you can't tell, I like this deal for the Pirates. Looks like a savvy move in my book.
The Mariners, with a few lucky breaks, could be in great position to take advantage of the bullpen market. They have a trio of right-handed relievers - Stephen Pryor, Carter Capps, and Tom Wilhelmsen - who have the potential to hold their own in late-inning relief roles (Shawn Kelley might be able to sneak into the conversation too). They also have a pair of southpaws, Charlie Furbush and Oliver Perez, who emerged last year. I believe one of them is expendable because both Bobby LaFramboise and Brian Moran are worth looks as second lefties in a bullpen right now.
Internally, the Mariners have a situation brewing where some relievers might be able to get the job done about as well as others, but the ones with value on the trade market will be the ones actually producing in significant roles. The Mariners can't take advantage of this market tendency yet because many of their bullpen arms aren't quite established producers at this point. However, come three or four more months right now, the story could (and hopefully will) change. This would also conveniently come at time when guys like Danny Hultzen, James Paxton, Mike Zunino, and Nick Franklin might be ready for the majors.
July feels like forever away, especially as I look out the window at a drab, goosebump-inciting sky. However, it is a forever that will hold more, and perhaps more interesting, options for the Mariners than the current offseason landscape. That's not to say that there aren't deals worth pursuing right now. There are. The options have dwindled though, and it's worth noting that the Mariners are poised to see many new opportunities develop as the season unfolds.