The latest in this admirable annual series features one less story (23 vs. 24) than last year's, and it might have been better if had included even fewer. Several of Dozois's selections are quite a stretch for ""best-of"" status, and they detract from the high standard set by the rest of his choices. The table of contents shows a number of newer and less-familiar names, though many regulars (Nancy Kress, Pat Cadigan, Bruce Sterling) appear. When they're good, these stories are very good: Sterling's delightful look at a future turned upside-down (""Sacred Cow""), veteran Brian W. Aldiss's tale of stolen memories (""Friendship Bridge""), relative newcomer Greg Egan's story of a future rife with bioengineering (""Chaff""), and Jack Cady's haunting novella, ""The Night We Buried Road Dog"" (which recently won the Nebula Award), among others, are excellent examples of the vitality and power that enlivens the genre's short fiction. But too many others run from mediocre and bland (Walter Jon Williams's ""Wall, Stone, Craft,"" Connie Willis's ""Death on the Nile"") to dragging and dull (Rebecca Ore's ""Alien Bootlegger,"" Ian R. MacLeod's ""Papa"") and even to laughably inept (neophyte G. David Nordley's ""Into the Miranda Rift""). Perhaps it was a slow year for short science fiction, but whatever the reason, this installment in Dozois's eminent series is a disappointment.