I've posted this in another thread, but I'll re-post it here, since it certainly qualifies as an "amazing Karlsson stat":
DEFENSEMEN CONTRIBUTION TO TEAM OFFENSE
Players | Season | Team | Points | TeamG | Percentage
Bobby Orr | 1970 | BOS | 120 | 277 | 43.3%
Bobby Orr | 1975 | BOS | 135 | 345 | 39.1%
Erik Karlsson
| 2016 | OTT | 82| 230 | 35.7%
Bobby Orr | 1972 | BOS | 117 | 330 | 35.5%
Bobby Orr | 1974 | BOS | 122 | 349 | 35%
Erik Karlsson
| 2017 | OTT | 72 | 206 | 35%
Bobby Orr | 1971 | BOS | 139 | 399 | 34.8%
Brent Burns | 2017 | SJS | 76 | 219 | 34.7%
Phil Housley | 1992 | WIN | 86 | 251 | 34.3%
Denis Potvin | 1976 | NYI | 98 | 297 | 33%
Paul Coffey | 1989 | PIT | 113 | 347 | 32.6%
Paul Coffey | 1990 | PIT | 103 | 318 | 32.4%
Paul Coffey | 1986 | EDM | 138 | 426 | 32.4%
Erik Karlsson
| 2014 | OTT | 74 | 229 | 32.3%
Paul Coffey | 1995 | DET | 58 | 180 | 32.2%
Erik Karlsson
| 2012 | OTT | 78 | 243 | 32.1%
Brian Leetch | 1992 | NYR | 102 | 321 | 31.8%
Ray Bourque | 1987 | BOS | 95 | 301 | 31.6%
Brian Leetch | 2001 | NYR | 79 | 250 | 31.6%
Ray Bourque | 1994 | BOS | 91 | 289 | 31.5%
This statistic looks at the percentage of their team's offense a defenseman has contributed to. I don't remember how far back the data goes, but it's at least to 1950, if not earlier.
As you'd expect, Bobby Orr dominates the list. He has the 1st, 2nd, 4th, 5th, and 7th highest-ranking seasons of all-time.
What was surprising is how well Karlsson fares. He ranks 3rd, 6th, 14th and 16th. He already has as many spots on the list as Coffey (but consistently ranks higher). He fares better than Bourque and Leetch. Most impressively, Orr and Karlsson combined to up all of the top seven positions.