At 5,280 feet above sea level, fastballs will possess more zip but less lift as they streak toward home plate.

Curveballs, meanwhile, will fly less curvaceously, while sliders will lose snap - tending to fly straighter than pitchers would wish.

Baseball is about physics as much as physical coordination and conditioning. And the atmospheric physics of mile-high Denver are markedly different from those of Boston-by-the-Sea.

"There will be a definite effect" on World Series games played in Denver, said Alan M. Nathan, a physicist at the University of Illinois at Urbana-Champaign, Maine native, and ardent citizen of Red Sox Nation. "It probably won't be a decisive effect, but it will be a real factor."

It's well known that Colorado's thinner air makes for longer hits, although scientists disagree over how much farther a ball walloped in Coors Field will travel than would the same slam at Fenway Park. Baseballs used at the Rockies' home field are these days stored in humidors to prevent drying that would make them even more defiant of gravity, but oft-cited calculations claim the gain remains on the order of 10 percent - meaning a ball slugged 400 feet at Fenway would travel 440 feet in Denver.

Maybe.

Nathan believes a 5 percent gain is more accurate. "That's a lot, but not as much as they like to say out there," he said.