Bentley appeared in 39 games in his rookie campaign with Chicago, scoring 12 goals and 19 points. His brother Max joined him early in the 1941–42 season, and the pair were placed on a line together. After two years of development with the Black Hawks, Bentley emerged as the NHL's scoring leader in 1942–43 with 73 points, a total that tied Cooney Weiland's NHL record for points in a season. He was the first Black Hawks player to finish as the scoring leader, and finished second in voting for the Hart Trophy as most valuable player.