Baseballs

In 1998, Rawlings manufactured more than 600,000 baseballs for Major League Baseball (MLB). Incredibly, one of them sold at auction for more than $3 million--about what MLB paid for half of its year's supply.

There wasn't anything special about that one ball until St. Louis Cardinal Mark McGwire smacked it for his 70th--and last--home run of the season, setting a new record.

In fact, there hasn't been anything new or different about the baseballs used by MLB since 1974, when the league changed the outside cover to cowhide; it had been horsehide, which was becoming in short supply.

MLB leaves no room for creativity in the manufacture of the balls it uses. Its official rules state: "The ball should be a sphere formed by yarn wound around a small sphere of cork, or rubber, or similar material covered with two stripes of white horsehide or cowhide, tightly stitched together. It shall weigh not less than 5 nor more than 51/4 oz avoirdupois and measure no less than 9 nor more than 91/4 inches in circumference."

The game of baseball, however, was not always such a bastion of uniformity. Early baseballs were made from the materials at hand and varied widely. As you can imagine, wrapping a walnut with string resulted in a ball very different in size and weight than one made by wrapping a stone with cloth, or even socks.

Today, instructions to the manufacturer call for the cork nucleus of prescribed weight (0.5 oz) and diameter (2.86 to 2.94 inches) to be encased in two thin rubber layers--one black, one red--weighing a total of 7/8 oz. The "pill," as it's called, is machine-wound under high, consistent tension with 121 yards of four-ply blue-gray wool yarn, 45 yards of three-ply white wool yarn, 53 more yards of three-ply wool yarn--this time blue-gray in color to denote the stage of manufacture, according to Rawlings--and 150 yards of fine white polyester-cotton blend yarn. This "center" is coated with rubber cement before the cover is put on.

The cover--two pieces of elongated figure-eight-shaped white cowhide--is dampened to permit stretching and hand-stitched together with exactly 216 raised stitches, using 88 inches of red cotton thread. The last step in the process is rolling the balls for 15 seconds while still slightly damp so the seams are even and reasonably flat.

But these balls aren't ready for the big leagues yet--they have to pass muster before they can take the field. The balls must meet the obvious physical standards--size, shape, and weight--as well as cosmetic appeal and something called liveliness, which is measured by a coefficient of restitution.

To ensure that balls used by MLB are uniformly lively, balls are selected at random from each shipment to be tested. They are shot from an air cannon at 85 feet per second at a wall made of northern white ash--the wood used to make bats. Each tested ball must bounce back at between 0.514 and 0.578 of its original speed to be suitably lively for MLB.

The tested balls must also prove their mettle in another way. They must retain their shape under pressure--distorting less than 0.08 inch after being subjected to a 6.5-lb force.

Manufacturing tolerances for baseballs were first set in the 1860s, when baseballs began to be made commercially, but a measure of variability remained. A ball made with a looser wrap played much differently than did a tightly wrapped ball. The size of the rubber pit used also made a difference in the liveliness of the ball.

These differences played a key strategic role in early professional baseball because the home team provided the game balls. A team with strong hitters would go for the tightly wound "lively" balls and might rack up more than 100 runs in a game. A strong defensive club opted for looser, softer--"dead"--balls that wouldn't sail so far when slugged.

The introduction of rubber-coated cork as the core of baseballs in the early 1910s resulted in an even livelier ball. An earlier experiment with a plain cork center was not successful because the wool yarn swelled after the ball was made.

Wily pitchers found ways around the benefits to batters of these lively balls. They increased their use of so-called freak deliveries, including spitballs and scuffballs, until the league outlawed the use of such doctored deliveries in 1920.

That ban on applying substances to--or otherwise changing the surface of--balls coincided with a seemingly inadvertent change in the baseballs themselves. The availability of finer, more resilient wool yarns, which had been going to the war effort, and improvements in the machinery used to manufacture the balls resulted in a tighter wound, still livelier ball.

During the 1921 season, pitchers complained that they couldn't get a good grip on the shiny, slick, undoctored surface. Umpires began rubbing the balls before games, a practice that continues today. MLB's official game-ball preparation calls for umpires to rub the balls with Lena Blackburne's Rubbing Mud, which one representative of the Major League Umpire's Association describes as smooth and creamy, but with a fine grit. The composition of the mud is a closely held proprietary secret, but the base ingredient is known to be mud from a specific site in a tributary of the Delaware River.

It may seem that pitchers have traditionally gotten the worst end of the innovation stick, but this year Rawlings introduced a baseball just for them--one with a built-in speedometer. It even comes with a warranty that's invalidated if the ball is hit with a bat. The company's Radar Ball measures the speed with which the ball is thrown at a calibrated distance. It has speed-sensing technology that involves a microchip processor and a liquid-crystal display to give the pitcher immediate feedback.

New and different is fine for the training of pitchers, but Rawlings is equally proud of the "same-old, same-old" aspect of the baseballs it manufactures for MLB. It seems ironic to me, though, that so much effort goes into leveling the playing field in a game where the pitcher stands on a mound. Robin Giroux

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Copyright © 1999 American Chemical Society