Here is Melancon's output pitching for Houston in 2011: These are mostly solid, if unspectacular numbers, but with a good strikeouts-to-walks ratio and manageable WHIP. Had he built on this in 2012, Melancon may have established himself as one of Boston's top relievers. Looking at his basic 2012 numbers, it appears as if he had a total collapse in performance this season. Overall, he posted a 6.20 ERA, allowing 8 home runs in only 45.1 innings of work. At a glance, this would make his acquisition by the Pirates appear questionable. Luckily for Melancon - and the Bucs - his ERA and home run totals are particularly misleading. They are heavily skewed by four disastrous April appearances in which he retired only 6 of 18 batters he faced, gave up 5 long balls and had a slugging percentage against of 1.733. His ERA in April was... wait for it... 49.50! Unsurprisingly, the Red Sox optioned him to AAA Pawtucket to see if he could recover his stuff and confidence.
This is where his performance across the rest of 2012 becomes interesting - and makes him much more appealing as a late-inning option out of the Bucco's bullpen in 2013. Melancon terrorized AAA hitters in 21 minor league games. In 21.2 innings, he allowed only 2 earned runs, struck out 27 batters (11.2 K/9), walked only 3 (1.2 BB/9), and posted a matching WHIP and ERA of 0.83. That's pretty dominant. Question is, could he perform adequately in the Majors? The Sox recalled him in June, and he pitched well that month. Passable results followed in July and August, but he was near unhittable in September, with opponents managing only .114/.162/.143 against him. If one ignores his April - and to be fair, A.J. Burnett routinely had his May 2, 2.2 IP, 12 ER debacle against St. Louis conveniently forgotten about by most people - then Melancon had a very respectable return in 2012. To quote myself:
@dejan_kovacevic After recall in June Melancon posted 4.18 ERA in 43 IP w/1.05 WHIP. Opponents hit only .217/.273/.323, 3HR. #JustSayingThe more you dig, the more evidence there is to be found that Melancon could be successful out of the 'pen for the Bucs. His strikeout rate climbed month-on-month throughout the season, from 4.5 K/9 in April, through 5.9 (June), 7.3 (July), 8.3 (August) to an outstanding 11.7 K/9 in September. This may well be due to increased velocity in his fastball later in the season, though I suspect increased confidence from his time at AAA also contributed.
— Nick Ferrier (@LordFezzington) December 23, 2012
The increased velocity may have a downside however, as - according to piratesprospects.com - he has a 'high-effort delivery'. He missed the whole of 2007 after injuring his elbow and undergoing Tommy John surgery whilst with New York. It will be interesting to see if he can continue to throw as hard as he did at the end of 2012 in 2013. Again according to Pirates Prospects, his repertoire is based around a mid-90s mph four-seamer and cutter, with a 12-6 power curve as his stock out pitch. Looking at FanGraphs, he appears to mix his pitches well so as not to be over-reliant on any one, and adds in a change-up now and again.
All in all, Melancon is - by far - the most important piece that Pirates' management will be relying on to make the Hanrahan trade a success. Clearly, he has the potential to do very well, with a ceiling at least as high as Hanrahan's was when he arrived in Pittsburgh in '09. The Pirates' staff have done an admirable job in getting the best out of relief pitchers in recent seasons. I see no reason why this shouldn't continue with Mark Melancon.
P.S. Just for reference, I have included Melancon's statistics in NL Central ballparks for the sake of completeness. The sample size is too small (given that Minute Maid Park will be in the AL West next year) to say very much, but these are the stadiums in which Melancon should see the most action in 2013. Enjoy!