Letang finished the year with the most assists (33) and finished tied with Subban for the most points by a defenseman (38), despite missing 13 games due to injury. In addition, Letang logged the seventh highest average ice-time (25:38), which included time on both the penalty kill (2:12 average) and power play (4:37 average).
Subban compiled a tremendous year in terms of his offensive production. In 42 games, he finished in the top three among defensemen with 11 goals and 27 assists for 38 points. However, the issue raised with Subban's potential for the Norris is his average ice time. He finished the regular season ranked 35th amongst defenseman with 23:14 per game, with an average of 4:42 on the power play and 1:27 on the penalty kill.
Suter finished the season averaging 27:16 of ice time per game (most in the league), which included 3:46 on the power play and 2:07 on the penalty kill. He played in all 48 games this season and registered 32 points (four goals, 28 assists), which ranked him third behind Letang and Subban. In addition, he finished second to Letang in assists.
Most believe Suter to be the front-runner, given that he played the full season and helped Minnesota into the playoffs without a ton of other solid defensemen.
Personally, I think Letang has a chance though. He's well-liked nationally by the media that votes for this award and his numbers pop out and sometimes sexy boxcar stats carry the day, like when Erik Karlsson won the Norris last season.
Either way, not the biggest deal in the world, but a cool recognition for Letang, who's definitely blossomed league-wide into one of the top defensemen around, and is being recognized as such. Which could make his negotiations with Ray Shero all the more interesting (Letang has one year after this on his contract and then would be an unrestricted free agent). But, as of right now as the Penguins are enveloped in the Stanley Cup playoffs that is the ultimate "later problem".