The Comedy of Murderfist and The Birthday Boys The sketch comedy group Murderfist begins every show like an English soccer riot, the unkempt members of the cast stomping around the stage, bouncing off one another, a blur of beer bottles, beards and bellies. Henry Zebrowski of Murderfist, a sketch comedy group that performs with a rough, visceral energy and a zeal for pushing the envelope of its material. As rock music blares, Ed Larson, a marauding bear of a man, yells like the professional wrestler Hacksaw Jim Duggan. Holden McNeely, a bespectacled comic who looks like a preppy hedge fund analyst down on his luck, flails, all arms and legs. John Moreno presents a stark contrast, adopting a dead-eyed calm that transforms into a threatening leer. Others preen, yell nonsensically and often look as if they were about to careen into the audience. Sketch seems to be everywhere these days. Often overshadowed by stand-up and improv, this live art form is a popular staple at theaters like the Upright Citizens Brigade and the Pit in Manhattan, and, as comedy expands on television, it has had a resurgence on cable. Comedy Central has built shows with passionate cult audiences around strong personalities like Amy Schumer, Nick Kroll and Key & Peele. IFC entered this crowded market this fall with "The Birthday Boys," a show starring a Los Angeles troupe of that name that is refined, cerebral, well groomed: the polar opposite of Murderfist. Murderfist, which performs on Friday at the Brooklyn Comedy Festival and on Saturday at the Pit in the Flatiron district, delivers on its promise of crude, punked-out chaos. The scenes are visceral and unpolished, full of spurting gore and exposed flesh. If a sex toy appears at the beginning of a scene, by the end, someone will fondle it. It's comedy that works in a theater, but is most at home in a bar (where the troupe sometimes plays). The joke often hinges on just how far the performers will go. When the subject is an awkward wedding toast, a classic comedy scenario, don't expect an embarrassingly off-key remark inspiring a few gasps. Instead, the groom's father (Henry Zebrowski) blurts, "I got AIDS from a gay drifter," which turns out to be the most appropriate thing he has to say. Before long, he tells his son: "Your mother and I stole you from a richer family. You could have had a better life. "The Birthday Boys" begins with the advantage of the comedy clout of Bob Odenkirk, who is an executive producer and also stars. Mr. Odenkirk, along with David Cross, created one of the best-written, funniest and most inventive sketch shows ever broadcast, "Mr. Show." Some of the same DNA is on display in "The Birthday Boys," whose gently absurdist parodies often turn in on themselves, with jokes that cross several sketches and slyly comment on others. The rigorously structured show is impressively precise about parody, particularly in capturing the language or look of a particular kind of television documentary or the costumes of Silicon Valley pioneers. The writing is often best in the details, such as a clever sketch that imagines a man leaving his accountant, except played in the style of a Hollywood romance. Every line captures a different acting cliché. When it comes to setting up the laugh, "The Birthday Boys" is patient, even to a fault. Like the IFC series that leads into it, the talk-show satire "Comedy Bang Bang," "The Birthday Boys" can sometimes seem as if it wanted to be smart more than funny. Mr. Odenkirk's starring role is a mixed blessing, since he draws attention away from his unknown colleagues, who often play bands of friends trying to make something that ends badly. These stories of plucky newcomers echo with the performers on this show, a self-awareness typical of their brand of comedy. It's hard to imagine Murderfist translating well to television. Its barreling, unruly energy benefits from being live. In one of the group's few directly satirical efforts, it sends up improv teachers. Acting gurus have been mocked for generations, but improv class is fresher territory, though the stand-up comic Todd Barry once finished a digressive bit by jokingly advertising his Upright Citizens Brigade class on riffing.