Matt Duffy had himself a season in 2015. The former twentieth round (20-9, 610th overall) draft pick in 2011 won the Pacific Coast League MVP this past season after posting a .294/.366/.484 slash line with an 8.6% walk ratio, a 16.2% strikeout ratio, a 127 wRC+, .376 wOBA, 20 home runs, an 18.4 wRAA, 51 extra base hits (out of 144 total hits, meaning 35% of his hits went for extra bases) and a .190 ISO. He also drove in 104 runs and scored 94 runs, for those who monitor those statistics.
In other words, he was really good last year at Triple-A.
He made his Major League debut as a September call-up for the Astros, and hit .375/.444/.500 in a microscopic (9 plate appearances, or 8 at bats) sample size. That included three hits, one of them a double, three runs driven in, and a walk.
It's (obviously) unlikely that that kind of success is repeatable immediately at the big league level for him. However, there is a very interesting aspect to his profile that still bodes well for him going forward. With the exception of the jump from A ball (where he spent the entire 2012 season) with the Lexington Legends (remember them?) to High-A in Lancaster (the juggernaut of the minor leagues, when it comes to offensive environments) to start the 2013 season, each jump in level he's made has been followed by a period in which he struggles a bit (relatively speaking) and then a period when he adjusts and performs really, really well.
Actually, more specifically, each time he's jumped a level mid-season (he jumped from A to High-A in two different seasons, with an offseason in between to prepare) he's struggled initially and then performed well after an adjustment.
For example, in 2013 he came out and lit up Lancaster for almost 500 plate appearances before earning himself a promotion to Corpus Christi for the final 24 games of the season. In those 24 games, he struggled some with an uncharacteristically low (3.2%, compared to a 7.1% in Lancaster all season and an 8.2% in Lexington the season before) walk rate and the highest strikeout rate (23.2%) of his professional career. His slash line was .247/.295/.461 and, while he was hitting the ball hard (five home runs and a .213 ISO in just 95 plate appearances), his wRC+ was a then-career low 112. Then, in 2014, he lept out of the gate by posting a .302/.340/.455 slash line with six home runs and a .153 ISO in 216 plate appearances in Double-A to begin the season. His walk rate stayed low at 3.2%, but he cut his strikeout rate down from the career high the year before to a much more manageable 16.7% in 2014. His wRC+, moreover, soared back up to 128. He earned a promotion to Triple-A.
Rinse and repeat.
He struggled more in his Triple-A debut than he had at any other point in his professional career, with a 100 wRC+ (league average) and an uninspiring .343 wOBA belying his otherwise not-terrible numbers (.279/.333/.448 slash line, 12 home runs in 352 plate appearances, .168 ISO, etc.) to close out the 2014 season.
Then, he won the MVP in 2015 at Triple-A.
That kind of adaptation with time to adjust and then an offseason to prepare bodes well for his chances of winning a roster spot with the Astros at the Major League level in Spring Training this year. It's no secret that all of the starting positions for the Astros are likely locked in on the offensive side of the ball...but there is a bench battle brewing between Duffy, Preston Tucker, and Tyler White. Healthy competition is good for everyone.
There are two distinct schools of thought on who of the three has the inside track for that elusive 25th spot on the Opening Day Roster. Preston Tucker seems to be the most likely from my perspective. Jake Marisnick and Marwin Gonzalez are already assured spots as defensive replacements off the bench, with Marwin adding a good pinch hit (or platoon) bat against left handed pitching. It seems that Tucker, the only left handed bat of the three and the only one of the three with significant playing time (and success) at the Major League Level so far, would have the inside track as the pinch-hit bat against right-handed pitchers.
However, there is just as strong an argument, if not stronger, that the Astros have a lot of left-handed bats already and might be more in need of a platooon option for the corner infield positions. With both infield starters (Luis Valbuena and Jon Singleton) at the corners being left handed bats, Marwin can only spell one of them at a time as a platoon partner. So there is a legitimate point of view that Duffy could very well make the Opening Day Roster in that capacity.
My bet is on him being the beneficiary of another mid-season promotion. Here's hoping his transition goes as well in the Major Leagues as it did when he transitioned into both Double-A and Triple-A. Either way, he appears to be in line to contribute quite a bit to the 2016 Houston Astros.