Magic Johnson, TV's newest talk-show host, might be well advised this weekend to rent Requiem for a Heavyweight, in which a dignified and worthy boxer, overtaken by age and circumstance, finds work wrestling in an Indian costume in front of screaming crowds. Reinvention as a late-night presence is a particularly cruel pension for any retired athlete. The talk-show format has become so reified that it accommodates only the most minuscule variations, which therefore take on outsize meaning. So in addition to the obligatory vulgar second banana and overly social bandleader, the furniture on Magic's stage set is so gigantic it made even him look small. The sketches -- gruesomely contrived exercises in make-pretend merriment -- just made him look sad. It wasn't polite to watch. You did the right thing by flipping back to the Bulls game.