One sketch does not a whole show make, but that one sets the benchmark for what Second City delivers when it's firing on all cylinders: a perfect balance of laughs that simultaneously go for the gut and the head. When it hits, it's a singular form of theatrical comedy that's made the troupe a Chicago fixture since 1959 and offered a distinct alternative on the Strip since 2001.

The five performers write their own material, and the new edition at the Flamingo Las Vegas retains three cast members -- Katie Neff, Paul Mattingly and Craig Uhlir -- and director Jim Carlson, who is charged with shaping their ideas into a cohesive whole.

The troupe returns to the raunchy treatment of grown-up themes from last year, spending a lot of time on the sexual politics that drive modern society at home and the office.

Locals or loyal fans who saw the last edition may be less impressed by a repeat attempt to tie it all up with the same hat trick of revisiting earlier sketches; this time it's less deft and suffers in comparison.

But it is hard to combine a series of sprints into a marathon, and a challenge to pace 75 minutes of sketches without any down time. Audience members tend to create their own rest breaks, perhaps explaining why this edition seems a bit front-loaded and peaks too soon.

But even the weaker sketches -- didn't a different cast do the same grown man-as-baby thing a few years ago? -- are better than most "Saturday Night Live" skits these days.

There's the 17-year-old (Archibald) who is a bit surprised that his divorced dad (Uhlir) isn't upset because he stumbled in at 6 a.m. "You're not gonna change the world, boy," Dad tells him before the two bond over the joys of hanging out at Wal-Mart.

There's Neff as a pregnant Army Reservist trying to escape the affections of fellow shopper Gossman, who just can't find enough ways to thank her for service to her country: "Can I buy your paper towels for you?"

Quoting the jokes here doesn't do justice to the quality of acting. The full cast shows its intricate timing on a bring-the-boyfriend (Mattingly)-home sketch, and so does a human resources "video" on political correctness in which the three guys break into a rap number: "Nappy 'ho! No way! Don't say!"

That one is immediately followed by Gossman's solo monologue as a proud hooker offering a self-help pep talk: "It is not too late to pursue your dream. I am living proof of that."

Second City never seems to do turnaway business on the Strip, but manages to stay solvent without prostituting itself to a lower standard of comedy.