John Carlson's offensive skills are not underrated. In fact, that is what he's known for.
Case in point: A recent article by Ben Raby of NHL.com about the separation of Carlson from his long-time defensive partner Karl Alzner described Alzner and Carlson, respectively: "One is a left-handed stay-at-home defenseman, the other a right-handed offensive-minded defenseman."
To further support this theory, Carlson's plus-minus rating of plus-nine leads all defenders and is second on the team. Meanwhile, Alzner's minus-five is second worst on the team.
But Carlson's plus-minus rating is boosted by his offense. He has six goals and is fifth on the team with 22 points. And Alzner's plus-minus is stunted by his lack of offense. Karl has all of four points on the season.
Plus-minus rating is an overrated statistic, however, and helps hide the fact that Carlson is an excellent defender. Several other statistics can help show just how good he really is at defense, thus revealing that he is indeed an underrated defender.
Carlson is second on the Caps' blueline with 52 hits, behind only John Erskine with 71. He leads Capitals defenders with 17 takeaways, while Alzner has six.
Carlson again leads all Washington defensmen with 111 blocked shots, ranking third in the entire NHL, only three behind the league leader. Alzner is second on the team with 76.
Perhaps the best way to prove how much John Carlson is valued as a defender is to look at how much Adam Oates trusts him as a penalty killer. Carlson is actually first on the Capitals defense with 2:45 of short-handed time on ice per game (SHTOI/G). Karl Alzner is second with 2:28.
It's a wonder why John Carlson is primarily described as an "offensive-minded defenseman".