Ask any Chicago Cubs or Boston Red Sox fan: winning baseball games isn't easy. In fact, scientists have played at trying to figure out the physics behind America's pastime for years. Now two reports explain the game's intricacies--from fielding a fly to hitting a homer--a little better.

Writing in today's issue of the journal Nature, Peter McLeod of the University of Oxford and his colleagues elucidate how outfielders track an approaching ball in order to make a play for it. The researchers propose that a player needs to keep two angles in mind: the vertical elevation of the ball and the angle (relative to his initial sighting of the ball) through which his gaze must shift horizontally to track the ball's trajectory. They found that when the optimum path to a fly ball is followed, the former angle increases at a variable rate, slowing over time, whereas the latter angle increases at a constant rate. Simulated ballplayers programmed to move under these constraints took similar routes to those taken by real outfielders in game situations. According to the report, this suggests that outfielders don't think about where the ball is likely to fall when they start running. As the authors note, "You do not know exactly where the ball will land, but you do know whether or not you will be able to intercept it. This presumably reflects the knowledge that you have been able to satisfy the constraints (or not)."

Findings published in the November issue of the American Journal of Physics, meanwhile, explain how hitters can increase their chances of avoiding the outfielders altogether by hitting home runs. Gregory S. Sawicki and Mont Hubbard of the University of California at Davis, together with William J. Stronge of the University of Cambridge, used improved models of the pitch, batting and flight phases of a baseball to investigate the criteria necessary for home run swings. They found that the most important factor for hitting one out of the park is the speed of the bat at the instant it connects with the ball--faster bats lead to longer hits. What the bat is made of has little effect, the team found, as the calculations for aluminum bats did not differ significantly from those for wooden ones. In addition, the researchers determined that "the optimally hit curveball will travel farther than both the fastball and knuckleball, because of beneficial topspin on the pitched curve ball that is enhanced during impact with the bat." To boost this enhancement, Hubbard notes, a player should hit a ball a bit below its center. Of course, it's unlikely that New York Yankee Aaron Boone was considering optimal angles and ball spin when he hit his 11th-inning home run to end the Red Sox's run toward this year's World Series.