CBS' "Golden Boy" (Tuesday, 9 p.m., Ch. 2) is another cop show, but it's not just another cop show. It's considerably better than most of what that genre has had to offer in recent years.It's the story of Walter Clark Jr. (Theo James), who - seven years in our future - will become the youngest police commissioner in the history of New York City. We meet him just slightly in our past, when he's a beat cop whose heroics bring him to the attention of the current police commissioner and get him promoted to homicide detective long before he's "made his bones."He's partnered with veteran detective Don Owen (Chi McBride), who has a lot to teach him if only Walter has the patience to learn. And he's so driven he doesn't have much patience.Three things set "Golden Boy" apart from the rest of the cop-show pack. First, the time-jumping gives each episode a framework - it shows us how Walter's future is influenced by his present, and how he gets where he's going.(It's the same device executive producer Greg Berlanti used stunningly well in the short-lived series "Jack & Bobby" - about a future president - and it adds depth to "Golden Boy," too.)Most of each episode is set in the present, and it's a really good cop drama filled with really good characters.Second, James and McBride - as well as their characters - have great chemistry.And third, Walter is a good guy who isn't always good. He sometimes does what's expedient, not what's right. He's not exactly an anti-hero, but you quickly discover the white hat doesn't fit. It's more a gray hat."Golden Boy" gets off to a very promising start."Golden Boy" airs this week and next (March 5) on Tuesdays at 9 p.m. ("Vegas" returns on March. 12.) "Golden Boy" moves to Fridays at 8 p.m. on March 8, replacing "CSI: NY," which has ended its season (and, possibly, its run).