For just about six years now, "30 Rock" has been one of the smartest shows on television. The sitcom's trademark wit and style come directly from the show's creator and head-writer Tina Fey. In the central character Liz Lemon, Fey has imbued many of her own qualities; though Fey is happily married with two daughters. In a way, the birth of Tina's second child actually wound up helping the show regain some of its bounce and snappiness.
In previous seasons, "30 Rock" started in September with the other Fall premiers. This gave the show from September to May to develop plot lines and gags with payoffs down the line. However, since Fey had been out on maternity leave at the time that production would have started on the show's sixth season, a decision was made to pick the show back up with a January premiere date, just about cleaving in half the amount of time the show had to build the season.
For some shows, it could be disastrous if they lost half their production run. However, in the case of "30 Rock," it may have forced the writers to come in with their feet on the ground, running. Within the first two or three episodes Liz's new boyfriend was introduced, played brilliantly by James Marsden. Marsden, like so many of Liz's other love interests, is not without his flaws. His name is Criss Chros after all! Normally it would've been a few more episodes in before the season's love interest was brought on.
Last week Mary Steenburgen came on the show, playing Jack Donaghy's mother-in-law. What a stroke of brilliance! Steenburgen's performance was pitch-perfect for the show, and watching her and Alec Baldwin dance around the issue of their characters' sexual attraction to one another was as entertaining as funny as anything in the last two seasons of the show.
Sure, maybe the fact the show has come out of the gate so strongly has nothing to do with the shortened season. Perhaps after about two decades writing comedy for "Saturday Night Live" and her own critically acclaimed show has given Fey super-human powers to create brilliant comedy no matter how much time she has to develop it. It just seems that the added element of a a dozen or so fewer episodes has forced Fey and company to ratchet up the pacing and tighten the comedy up just a bit more than they'd have had gotten to do with a full-length season.

