Except for those who operate from a rectangular slab of white rubber in mid-diamond, it has been—as everybody knows by now—a sparse season for baseball. And any farsighted hopes of filling the batting void must go farther than the current rookie crop. None of the first-year men excites memories of a young Mantle or Mays and, in fact, 19 of the 32 who have seen extended action are pitchers. The best of the lot is the Mets' Jerry Koosman, a 25-year-old from Appleton, Minn. with a 16-7 record, 1.87 earned run average and six shutouts—one short of the National League rookie record. Then there are the Yankees' Stan Bahnsen (2.13 ERA), the Angels' Tom Murphy (2.17), Pittsburgh's Bob Moose (2.41) and Cleveland Reliever Vicente Romo (1.58). So much for those who emulate their elders. The only batting upstart is Cincinnati Catcher John Bench, a 20-year-old who ranks among the team leaders in three categories for the league's best hitting squad. In spring training, Reds' Manager Dave Bristol indicated Bench would be a big asset if he hit .220. He is now at .275 with 61 RBIs and drawing raves from people like Cardinal Manager Red Schoendienst, who says, "I've never seen a better catcher." After Bench, it is a long drop to Giant speedster Bobby Bonds (.252), hailed as Willie Mays' successor in center; Washington's Del Unser (.239); Houston's Hector Torres (.231) and Baltimore's Elrod Hendricks (.227). At least Unser and Torres have some consolation—both are hitting better than they did in the minors. For the fans, there is also a glimmer of hope. Of the first 20 selections in the June free-agent draft, 11 were outfielders and only four were partial to that rectangular white slab.