Mike Johnston fared about as well as expected as a rookie coach in the 2014–15 season. The numbers stack up well against other coaches debuts, while Johnston arguably faced greater challenges and adversity throughout the season, namely injury and salary cap woes.
Of 12 NHL coaches, only five finished debut seasons with higher win percentages compared to a 0.598 win percentage by Johnston. Five of the 12, including Johnston, lost in the first round of the postseason, while only two advanced past the second round.
Mike Babcock guided the 2002–2003 Mighty Ducks of Anaheim to the Stanley Cup Final against the New Jersey Devils backed mostly by the scorching hot goaltending of Jean-Sebastien Giguere. Giguere played so out of the ordinary, becoming only the fifth player in NHL history to be awarded the playoff MVP trophy despite playing on the losing team, and the first since 1987.
Bob Hartley took the 1998–1999 Colorado Avalanche to the Conference Finals with a roster arguably better than the 2014–15 Penguins, highlighted by Peter Forsberg, Joe Sakic, and Patrick Roy.
Next comes in the issue of injuries. The Penguins finished second among all teams and first among playoff teams in “Time Missed Impact To Team,” a metric measuring the impact a team loses from a player missing playing time for any reason.
Only the Columbus Blue Jackets finished with a higher TMIT aggregate number, losing several key blueliners and Sergei Bobrovsky for stretches throughout the season, but the Penguins actually far and away beat out every team in goals and points totals lost due to injured players. Kris Letang, Evgeni Malkin and Patric Hornqvist all finished in the top 10 of TMIT points.
Keep in mind, salary cap problems coupled with the injuries forced Johnston to play with a depleted lineup and only five available defenders near the end of the season. General Manager Jim Rutherford admirably addressed the cap issues in the offseason, giving Johnston and the Penguins better depth to work with and adding speed and scoring to the lineup.
After a season of learning the new system implemented by Johnston, a tighter defensive system compared to the run-and-gun style of predecessor Dan Bylsma, expect the Penguins to be far better off in the second year of the Johnston tenure.