Derek Roy is a hard player to get a read on for sure. At 5'9" and 184 lbs, the first thing that stands out is his lack of size. It's tempting to say he wouldn't have been an NHLer if not for the rule changes following the lockout, but people forget that after a prolific OHL career in Kitchener (335 points in 242 games), and major success in the AHL (107 points in 101 games), he also played 49 games in the 2003-04 season with the Sabres and notched 19 points, without much PP time, and only about 15 minutes a night total. He was a feisty player, and strong for his size, so perhaps he could've had success even in a different time.
Regardless, it seems certain that the rule changes definitely enhanced his impact at the NHL level. Following the lockout, from ages 22-24 he posted increasing totals of 46 --> 63 --> 81 points on perhaps the best Sabres' teams of all time. This was good enough for 190 points in 223 games, behind only Vanek (196 in 245) on the team in that span, and trailing only Briere, Drury, and Afinogenov on a per-game basis. Certainly in this early stage, his success has to be attributed to his role. On a deep, contending Sabres team, he was the clear #3 behind Briere & Drury, and played regularly with Vanek & Afinogenov (two of the team's most prolific scoring wingers) against other teams' 3rd line competition. Roy was never a huge goalscorer, cracking 30 goals only once, and 25 goals only three times total. He had about 1.7 assists for every goal he scored in those first three post-lockout years.
In his 'peak' years of 2007-2011, he was 32nd in the NHL in points, and 30th in points per game. After that, he was injured and never really recovered to the same scoring level, bouncing around the NHL in his late 20s/early 30s before being forced to ply his talents in Europe, where he still is now. Remember that this peak was after the time that Drury & Briere had left Buffalo. Even though they were no longer a formidable force at the top of the NHL, Roy was the defacto #1 centre (and perhaps even forward) of those teams, and still managed to be a top 35 overall scoring forward in the NHL. This at least suggests that he was a capable #1 centre at his peak.
From memory and watching some old highlight packs...he was a relatively quick player for his size. Maybe not the most end to end speed, but he had agility, and was slippery with the puck. He had good hands, and could evade checks well. His big strength was his playmaking. He moved the puck quickly and decisively to his wingers, and facilitated the puck on the PP well. He certainly wasn't afraid to go to the net and grab a rebound or deflection either. He had a pretty good backhand.
Current comparable...I can't think of one off the top of my head. Maybe Vincent Trocheck? Relatively similar in size, both a little underrated, and playing the early part of their careers behind a better centre (Briere/Barkov). Trocheck seems to be a bit more of a goalscorer than Roy was, and there are certainly other dissimilarities between the two, but that's the best I can come up with now.
