TV Winners and Losers

TOP COP (From left) ''L.A. Dragnet'''s Eva Longoria, Evan Parke, Ed O'Neill, Christina Chang, and Desmond Harrington

L.A. Dragnet: Bob D'Amico/ABC

Saturday

TIME-SLOT SHOWDOWN ''Showdown'' may be too strong a word to describe any matchup on this night. (''America's Most Wanted'' versus...''Hack''?) But let's just say that a situation was created when ABC moved its sophomore cop drama ''L.A. Dragnet'' against CBS' ''The District.'' ''We were hopeful because Saturday at 10 p.m. is less competitive,'' says Bader. ''But the show never even really got sampled.'' Indeed, ''The District'' (No. 43) laid down the law against ''Dragnet'' (No. 101), proving once again that Craig T. Nelson is judge, jury, and executioner.

GAME CHANGER In a reality duel beginning mid-January, CBS will pit its resuscitation of ''Star Search'' against the indefatigable ''COPS.'' Who says Arsenio Hall can't even get arrested?