Cooper helped the Tampa Lightning finish second in the Atlantic Division with a 50-26-6 record and clinch their ninth-straight playoff berth. During the regular season, the Lightning were fourth in goals-per game (3.49), third in goals-against per game (2.79), and ranked third on the power play (82.6 percent).
A three-time finalist, Cooper finished as runner up to Barry Trotz of the New York Islanders in 2018-19, and was third in 2013-14. The 58-year-old would be the first Lightning coach to win the award since John Tortorella in 2003-04.
In his first season as a head coach, Muse guided the Pittsburgh Penguins to their first playoff berth in four seasons. Pittsburgh (41-25-16) finished second in the Metropolitan Division and improved by 18 points from last season. The Penguins used an NHL-high 44 players this season, but still scored the third-most goals per game (3.54), were seventh on the power play (24.1 percent) and tied for sixth on the penalty kill (81.4 percent).
Muse would be the first rookie coach to win the award since Patrick Roy for the Colorado Avalanche in 2013-14. The 43-year-old also would be the first Penguins coach to win the award since Dan Bylsma in 2010-11.
In his second season in his second stint with the Buffalo Sabres, Ruff led one of the more remarkable turnarounds in NHL history. The Sabres were 11-13-4 and last in the Eastern Conference on Dec. 5 before ending the season on a 39-10-5 run to win the Atlantic Division with a 50-23-9 record, their first division title since 2009-10 and break their NHL-record 14-season playoff drought. The Sabres had a 30-point improvement from last season, when they finished 26th in the NHL standings.
Buffalo was fifth with 3.45 goals-per game and tied for 10th allowing 2.93 per game after finishing 20th in the NHL last season, allowing 3.50 per game.
Ruff, 66, is a finalist for the fifth time, tying an NHL record with Tortorella, Scotty Bowman, and Alain Vigneault. Ruff won the award with the Sabres in 2005-06 and has finished runner-up twice and third once.
"That just means that our coaching staff did one (heck) of a job," Ruff said. "This isn't a one-man job and the hours these guys have put in and where we got to, a complete team effort."
Spencer Carbery of the Washington Capitals won the Adams Award last season.
