The only goal that he has been on for in the last two best on best tournament was the 3 on 3 goal. That's no regulation goals against in 10 games and has also led Team Sweden in scoring for both tourneys.
That's a stat line of
GP 10 G: 5 A: 7 P: 12 and a +6
Just super impressive that a defensive liability can go two straight tournaments without being scored on.
Norris favourite 2017?
The problem there is drawing conclusions on a very small sample size. Even playing the exact same way, a player will have 10-game periods of great stats and equal periods of awful stats.
With that said, one thing I've learned over my time here is that a lot of people have a very limited definition of defensive play. Often it becomes a question of being tough in the corners/in front of the net, and mistakes made on the breakout.
Karlsson to me has some holes in his defensive game, but he is overall very effective. He's terrific at defending the transition in the offensive zone, neutral zone and at the blueline. I've read that he's one of the most effective in the league at defending against controlled zone entries. Like many guys with great skating, he has the ability to contain players while maintaining stick positioning so they can't make dangerous passes. His overall positioning is good but spotty. He wins the puck by using his skating to establish body positioning, and with his terrific stick work. He's getting continuously better at tying up sticks in front of the net. He isn't as consistent in his defensive work as you'd like, but will likely get better in that regard with experience. His weakness is getting attacked with skill, honestly. He's a bit susceptible to being dangled. And finally, his breakout and transition game is the best. Any time you screw up offensively near him, the puck is gone.
All in all, he's pretty good both ways. To be honest, I find that his offensive side is a bit too lauded due to deployment and how central he is systemically to the Senators offense, while he gets way too much criticism for his defense.