CHICAGO - For the U.S. Air Force Thunderbirds, it was flying practice. For the Chicago Cubs, batting practice. Pilots prepared for the weekend’s Chicago Air & Water Show by zipping their loud jets tantalizingly close to Wrigley Field’s upper deck during yesterday’s second inning. The Cubs, meanwhile, were making noise with their bats.

PITTSBURGH - The Pittsburgh Pirates may soon find out if an investment of $20,000 can produce a couple of million-dollar arms. Rinku Singh and Dinesh Patel, their two India-born pitchers who had never seen a baseball game before being the top two finishers in a TV reality show, are nearly ready to make their professional debuts. Neither had picked up a baseball, much less thrown one, until little more than a year ago. Aspiring cricket players, they had no idea that American athletes could make so much money playing a sport they knew nothing about.

Roberto Clemente’s first hit and Babe Ruth’s parting shot occurred within the confines of the most spacious ballpark any major league baseball team called home. So did Bill Mazeroski’s 1960 World Series Game 7 homer, one so improbable, so magical that it seems certain to live in baseball’s memory bank as long as the sport exists. The first fireworks night and last tripleheader? Chuck Noll’s first home game as the Steelers’ coach? The first live broadcasts of major league baseball and college football? Forbes Field was home to all of that and much more during 61 eventful years that helped launch not one but, eventually, two ballpark-building construction binges.