The updated forecasts are calling for northwest winds -- that is, blowing in from left-center at Citizens Bank Park -- gusting to 28 m.p.h. on Saturday night. Given that the starting pitchers, Roy Halladay for the Phils and rival Tim Lincecum throw 90-plus fastballs over a short distance, and given that both have well-established expertise, one might wonder what difference a little wind would make. Physicist Alan M. Nathan, an emeritus professor at the University of Illinois, has done more than wonder. Take the case of a 95 m.p.h. wind thrown in a 20 m.p.h. tailwind. Nathan assumes a 54-foot flight from the point of release to home plate. Those radar guns pick up the speed near the point of release, but the ball slows down about 10 percent by the time it approaches the hitter. So Nathan estimates an average flight speed of 90.5. The entire trip takes a dizzying .407 seconds. That tailwind bumps up the average speed to 91.5, cutting the trip time to .402 seconds -- and the already precious reaction time. "The ball is going to arrive a little bit quicker," he said. The calculation may not be a perfect match to Saturday's situation. The wind speeds may be quite variable, and the forecasts hinge on a coastal storm that hasn't yet formed. But you get the idea. A tailwind might have one favorable effect for the hitters. Breaking balls would lose some of their sinking actions, says Nathan, and thus might tend to stay up in hitting zones. Unfortunately, the projected wind angle Saturday night, slicing in from left-center toward the first-base line, also might give an extra bite to curve balls breaking toward the right side of the plate. All in all, it looks like a tough night for the hitters. Even if the winds are calm. ..