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.
It's in the pitching game, however, that the Red Sox are most likely to feel Rocky Mountain lows.
Physicists say the reduced air pressure will give a slight edge to batters because fewer molecules in the air mean a pitched ball will have less substance on which to "bite," causing it to break, or swerve, less dramatically. The milder the break, the more easily a batter can read the ball's speed and trajectory.
That could spell trouble for pitchers used to the denser air of the Atlantic seaboard - the Red Sox have rarely played at nosebleed altitude (three Denver games in 2004, an exhibition in 1999). Rockies players face the same physics, of course, but are used to thinner air.
"For the Red Sox, it's going to feel different playing in Denver than other major league stadiums," said Barry Zink, a physicist at the University of Denver and a Rockies partisan.
"I expect the difference will be most felt by [Boston] pitchers," Zink said. "Breaking pitches will break less. Fastballs will pick up a little speed, but rise less . . . because they are moving through a thinner fluid," or air.
The difficulty of pitching in Denver is hardly news. "It's a tough place to pitch," said the Red Sox' Curt Schilling. "I don't know that anybody comes and pitches in Coors Field on a consistent basis and has good numbers."
