Cook's offence declined in 1928–29 as he recorded only 18 points. Attempting to defend their championship, the Rangers reached the 1929 Stanley Cup Final, but were defeated by the Boston Bruins. The 1929–30 season was statistically Cook's best in professional hockey. He finished tenth in the NHL with 24 goals and totaled 43 points in 44 games. Following a 35-point season in 1930–31, he was named to the inaugural NHL All-Star Team as the second team left wing. Cook scored 34 points the following season. The Rangers won the American Division title and reached the 1932 Stanley Cup Final but lost the series to the Toronto Maple Leafs.