It isn't often that the proverbial "local boy" makes good in his own home town in baseball, but "Al" Brancato is one who threatens to do so. While batting averages may indicate that Brancato has a long way to go before he can make the major league grade, the 21-year- old Philadelphian has shown enough promise to be kept on by Connie Mack's Athletics. Brancato came up from Williamsport, in the Eastern League, at the end of the 1939 season. He led the Eastern League in runs-batted-in with 98, despite a .280 average. Last year, in his first full season with the A's, while batting only .191 in 107 games, he drove in 23 runs on 57 hits to prove his timeliness.