By Hannah Holmes If you've ever hacked open a baseball, you may have wondered how the skin got sewn on there. (If you haven't ever hacked open a baseball, there's still time.) What mechanized needle could possibly plunge down through a baseball's leather skin, hang a left turn, and pop up through the next hole? How could this sewing machine maintain the precise string tension that produces those perfect, gentle nubs along the seam? On the phone, Steve Johnson sighs. He's the guy whose job at Rawlings Sporting Goods is to lose sleep over leather quality and wool supply as the demand for professional balls explodes. "We worked on a machine for about 10 years," he says sadly. "Ten years. It just never would work."

It turns out that every baseball on the planet (excluding the rubber ones whose stitches are carefully crafted to look like the real thing) is sewn together by hand. .

A baseball begins life as a "pill," a small sphere of cork and rubber enclosed in a rubber shell. The pill is tightly wound with three different layers of wool yarn, then finished with a winding of cotton/polyester yarn. This "core" is coated with a latex adhesive. It is this gooey and extremely hard lump over which an extremely tight-fitting jacket of leather must be sewn. The resulting ball must weigh between 5 and 5.25 ounces and have a circumference between 9 and 9.25 inches. Although China produces 80 percent of the world's baseballs, every single baseball pitched in the Major Leagues is made in a Costa Rican factory owned by Rawlings. There 1,000 baseball sewing experts start their day seated in front of a special vice holding a gooey baseball with a gluey leather cover wrapped around it. The leather is already punched with 108 stitching holes and is dampened to make it pliable.

With a custom-made needle in each hand, the sewer begins at the "neck," or the narrow part of the cover, and makes about seven stitches down the seam. .

Then, using pliers, she jabs the needles into the guts of the ball, traveling back under those stitches, and emerging just beyond the first hole she stitched. She continues sewing in this direction, using a foot-pedal on her vice to spin new sections of seam into reach. When she returns to the neck of the ball, her last stitches dive into the guts again, cross under the neck, come up through a hole and are snipped off. "The first time I sewed a baseball, it took me 45 minutes," Johnson recalls. Pros sew four to six an hour, achieving perfect string tension by feel. A wooden press rolls the seams flat, and finished balls are stored in a dehumidifying room that shrinks the covers tight and protects the balls from tropical humidity that might make them bloat illegally. All this labor keeps baseballs pricey. In fact winning teams used to keep the used balls at the end of a game, and fans had to give back any they caught in the stands.

At about $4 each, even by the thousands, professional baseballs still aren't cheap. But they're a real crowd pleaser. .

"I think they're throwing more of them into the stands," Johnson complains of the players. "We put so much energy into making a professional baseball, and its average life is about six minutes. I've actually been at games where I was hoping they wouldn't hit fouls." When you hack open your baseball, don't tell Steve Johnson.

Vocabulary Blem, v. A baseball that turns out too skinny, too hefty or otherwise off-spec, is "blemmed." It's stamped "blem," for blemish, and sold as a practice ball. Copyright © 1997 Discovery Communications, Inc.