Boston College hockey alum Mark Dennehy became head coach of the Merrimack Warriors in 2005-06, at a time when Merrimack had historically finished either last or second to last pretty much every year in its history.
The Warriors went 6-23-5 in his first year, and 3-27-4 in his second. But by year 5, Merrimack put together a 6th place finish in the conference and made the league playoffs for the first time since the league expanded beyond the point of every team qualifying. And then in 2010-11, Merrimack burst on to the national scene, posting a 25-10-4 record and making the NCAA hockey tournament, also pushing BC in the Hockey East tournament final that year before falling on a late BC game winner.