Dec. 16. 2011: With his third assist of the game, on Zenon Konopka's second-period goal in a 6-4 victory against the Penguins, Karlsson reaches 100 points in his NHL career.
Jan. 29, 2012: In his home rink, Karlsson plays in his second All-Star Game but does not get a point.
June 19, 2012: Karlsson signs a seven-year contract with the Senators, which runs through the 2018-19 season.
June 21, 2012: Two days after signing his contract, Karlsson wins his first Norris Trophy as the top defenseman in the NHL. He has 78 points (19 goals, 59 assists) in 81 games, 25 more than the next defensemen (Dustin Byfuglien and Brian Campbell).
Feb. 13, 2013: Karlsson sustains a lacerated Achilles tendon in his left leg when Penguins forward Matt Cooke's skate cuts him. He has surgery and is expected to miss 4-6 months.
April 25, 2013: Ten weeks to the day of the injury, Karlsson returns against the Washington Capitals. He has two assists, including the primary assist on Sergei Gonchar's overtime goal, in a 2-1 win.
Dec. 23, 2013: Karlsson's third point of the game, an assist on a goal by Kyle Turris in the third period of a 5-0 Senators win against the Penguins, is the 200th point of his NHL career.
Feb. 23, 2014:Karlsson wins a silver medal with Sweden when they are defeated by Canada 3-0 in the gold medal game at the 2014 Sochi Olympics. His eight points are tied for the tournament lead and he's named to the Olympic All-Star team and named the best defenseman in the tournament.
Oct. 2. 2014:Karlsson is named the ninth captain in Senators history, replacing Jason Spezza, who was traded to Dallas on July 1, 2014.
April 4, 2015: With an assist on Clarke MacArthur's first-period power-play goal, Karlsson gets his 300th NHL point in a 4-3 overtime win against the Capitals. Karlsson (393 games) becomes the fastest defenseman to reach the mark in 17 years (Sergei Zubov reached 300 points in 354 games, Jan. 11, 1998).
June 24, 2015: Karlsson wins his second Norris Trophy after scoring an NHL career-high 21 goals and leading defensemen in points with 66 in 82 games.