Crossballs, the recently premiered half hour that spoofs exactly what its title suggests unfortunately doesn't swipe at what's most ripe for ridicule -- their pointless clinging to the fraying labels of ''liberalism'' (now most often wishy-washy centrism) and ''conservatism'' (which has taken a radically hard-right turn). Instead, ''Crossballs'' does something that's just unfunny and confusing. It injects reality TV foolishness into its concept. A comic actor such as Matt Besser, an otherwise adroit member of the ferocious comedy troupe the Upright Citizens Brigade, coarsens his usual approach, promoting, in one episode, the notion that ''a sober teen is a dangerous teen'' because the kid will have his mischievous wits about him. Better, this character contends, the teenager be stoned and paranoid so he gets busted and is kept in line. Get it? This and other characters Besser plays are pitted, the show asserts, against unwitting civilians who think ''Crossballs'' is an actual debate show. Mixing real people with comics, and having the proceedings led by a fatuous host played by Chris Tallman (who's appeared in funnier bits on ''Reno 911!''), results in few laughs.