SYOSSET, N.Y. — Five years into the job, Islanders Coach Jack Capuano still straps a whistle to his left glove and uses it liberally at practice. He covers the rink like a Zamboni, rushing from one end to the other, smacking his stick on the ice to make a point.
As a left-handed-shooting defenseman from Cranston, R.I., Capuano appeared in only six N.H.L. games. But he is more than 400 games into his N.H.L. coaching career — in which he started as an interim coach.
The Islanders have assembled enough talent to become contenders, but Capuano continues to peer at video late into the night, looking for an edge that would lift the Islanders not only to a third Stanley Cup playoff berth in four years, but also to the franchise’s first playoff series victory in 23 years.