The Rangers made their NHL debut on November 16, 1926, against the Maroons. Cook scored the franchise's first goal, which also stood up as the winner, in a 1–0 victory. Appearing in 44 games, he led the league in both goals, 33, and points, 37. He finished as the runner-up to Herb Gardiner of the Montreal Canadiens for the Hart Trophy as the NHL's most valuable player. The Rangers finished first in the American Division, but were eliminated by the Boston Bruins in the playoffs. Cook recorded 24 points in 1927–28, the seventh highest total in the league. The Rangers again qualified for the playoffs, where they defeated the Pittsburgh Pirates, Boston Bruins and Montreal Maroons to win the franchise's first Stanley Cup championship. The Bread Line scored every Rangers goal in the 1928 Stanley Cup Finals.