The Avalanche didn’t deserve to win Monday because its high-powered offense wasn’t clicking against the New York Islanders and the goaltending was again below average. Goalie Semyon Varlamov stopped just 17-of-20 shots for a .850 save percentage — the fourth time in his last five starts that number has been below .900. The Islanders went 2-for-4 on the power play and won 4-1 at the Pepsi Center. Varlamov has allowed 21 goals in five games since backstopping the Avs to a 2-0 triumph Dec.