TRIPLE PLAY

At Union High, Willi Baedecker, a German emigre, learns American ways, is a sensible victor in a track field-diamond rivalry with a contemporary from another school, convinces his parents of the value of sports. But Willi's is a lumbering story -- a trudge rather than a yell and a leap from locker room to field. His home, complete with a television set is a weak offset to the almost equally limpidly described classroom frustrations and incidentally excellent outfielding. Too bad, for in spite of the heaviness, situations like the English teacher's insistent, unjustified demands and Willi's best pal's admonitions about kidding, provide some genuine hits.