The strongest evidence suggests that the reason for the difference is the ball, which, oddly enough, has been produced by Rawlings before. Under an agreement with Spalding, Rawlings provided some of the balls in 1971 and '72 and most of them in '73. Spalding, which had manufactured the balls for both leagues since their inceptions in 1876 and 1901, got out of the business this year.
No matter who is turning them out, the balls should not be either "live" or "dead." After all, the ingredients have always been the same: a hide cover, 150 yards of fine cotton, 219 yards of gray and white wool and a cork core surrounded by black and red rubber. Consistency is supposed to be ensured through adherence to specifications for weight (5 to 5.25 ounces), circumference (9 to 9.25 inches) and resilience (a coefficient of restitution of 51.4% to 57.8%). However, as batting statistics and tests show, all balls are not the same, not only from year to year but also from box to box.