Complex sentence: The Islanders have never won the Presidents' Trophy, although they led the NHL in regular season points three times before the league began awarding the trophy, winning the Stanley Cup in two out of the three seasons.
Split into simpler sentences: The Islanders have never won the Presidents' Trophy, although they led the NHL in regular season points three times before the league began awarding the trophy. They won the Stanley Cup in two out of the three seasons.