In the 1976 World Tournament (at Asbury Park, NJ), the balls were the special bicentennial design from Hyatt. I happened to bring my ball gauge -- two holes, one with the maximum permitted diameter and one with the minimum, which is to say 2.25 plus and minus 0.005 inches. Most of the 3, 5, and 7 balls hung up on larger hole when the eyes (areas with the numbers) had to clear. You can see where the ball hangs up by the light through the other parts of the hole. I assume that Hyatt had just rushed production of the commemorative balls.