Regional humorist Hess (The Maggody Militia, p. 175, etc.) joins series editors Gorman and Greenberg for this sixth annual roundup. Though the numbers of original collections helpfully listed by Jon L. Breen and Edward D. Hoch suggest that it's been a bumper year for short mystery fiction, a few formulas (the schemer outschemed, the just vengeance, the psychopathology of everyday life) predominate, so that the keynote here is professional accomplishment--reliable entertainers like Ruth Rendell, Marcia Muller, Ed McBain, Reginald Hill, Donald E. Westlake, and Sara Paretsky buff their wares to a high sheen- -without any particular originality. The exceptions, as always, are worth the money: Walter Satterthwait's secret-ingredient cassoulet, David Corn's macabre fictional confessional, Alan Russell's prison bridal tale, Bill Pronzini's paranoid suburban vignette. But the best story of all, S.J. Rozan's inner-city whodunit ``Hoops,'' is in many ways the most traditional. Clearly the best-edited annual, though not as distinctive in its choices as its latest competitor (see below).