One day last week at Chicago's White Sox Park the players were rewarded with books of Green Stamps for hitting home runs (10 books) or knocking in a run (five books), etc. In one game against the Twins, the Sox's star left-hander, Gary Peters, almost drove the Green Stamp people out of business. He picked up 16 books for striking out eight batters in the 11 innings he pitched, but he earned even more from his work at the plate. He went 3 for 5 and had three RBIs and a home run in a game the Sox won 5-4 in 13 innings. In all, he took home 45 books of stamps and raised his batting average to .284, second highest on the team. Peters' hitting ability is no fluke. He was originally signed as a first baseman, and last year he led the American League pitchers with a .259 average. Not bad for a rookie. This year he is hitting even better and already has three homers to equal his output of a year ago. One of the home runs was a pinch hit that won a game for the Sox two weeks ago in the 13th inning. On top of this, Peters also happens to be one of the very best pitchers around. Last year he was the Rookie of the Year and had the best ERA (2.33) in the league. This year he is already 12-5 and has a 2.49 ERA. Late last week, lest anyone forget that he is primarily a pitcher, Peters threw a three-hit shutout at the Detroit Tigers but went 0 for 4 at the plate. His average dropped down to .270—now only the third best mark on the weak-hitting White Sox.