The pennants and popcorn and hot dogs are all here, but we see them being delivered at 7:30 a.m. to Boston's Fenway Park. Jaspersohn opens with an impressively hushed six a.m. shot looking down past empty bleachers; and before game time we see crewmen hanging the players' laundry, grooming the field (the pitcher's mound takes an hour), laying out brownies and toiletries for the visiting team, and performing all the other chores that go unobserved by most ball-park visitors. Jaspersohn shows us the players arriving and warming up, the vendors loading and reloading, and the home-plate umpire rubbing today's 60 baseballs with ""a special mud from near the Delaware River."" He tells us how many children get lost at an average game, describes the photographers' cameras, and shows us the many jobs involved in the electronic message board and the TV news coverage. Once in a while we get a glimpse of the 1-0 game in progress, and we see a double-page section of the cheering crowd of 35,000 when Fred Lynn makes the hit that results in the single run. The clean-up crew puts in eight hours after the game; the reporters and teletypists get out their stories; the players take off for Baltimore; and the park is still again. Original hand-gathered material, an attractive you-are-there precision, a direct, often lyrical style free of sportswriterese, and the author's evident love for the game: all place this with that minority of sports-related juveniles worth stocking for more than topical book bait.