 Complete the following phrase:  In 1888 the college football rules convention voted to allow tackling below the waist. Players and coaches soon regarded pads as essential for the game. However, as in the National Hockey League during the 1970s, helmets were the last thing to be accepted. They were not a mandatory piece of equipment in college gridiron until 1939 and were not made mandatory in the National Football League until 1943 As a side note, the last NFL player to play in a game without a helmet was Dick Plasman an end for the Chicago Bears in 1940. There is a photograph of him without one taken during the 