The ubiquitous Duplass brothers stoke the furnace of sibling tension in this single-minded but fascinating discomfiture comedy, a kind of secret twin study of brothers locked in neurotic battle. In The Do-Deca-Pentathlon, Mark (Steve Zissis) is a chubby family man heading to his mother's house for his birthday; older brother Jeremy (Mark Kelly) is a poker-tourney bachelor beast arriving uninvited. Against everyone's better judgment, the two launch into a rematch of the childish Who's Best? 25-event competition that estranged them permanently in high school.

The Duplasses, maybe working through their own brotherly shit, craft this ordeal sneakily — the put-upon, teddy-bear dad slowly uncorks into a never-say-die juggernaut while the scumbag brother begins to grow up, even as the two must conspire to keep the Olympics secret from Mark's wary and sometimes terrified wife (Jennifer Lafleur).

Uncompromising in its way, the film's portrait of codependent compulsion is so organically conceived, you start to smell the sulfur of traumatized childhood, no exposition needed. (The boys' absent father is barely mentioned.) The cast begins in that mumblecore mode of quietly overreacting to everything, but once the testosterone starts oozing, the characters jump out into four substantial dimensions.

THE DO-DECA-PENTATHLON | Written and directed by Jay and Mark Duplass | Red Flag Releasing | Cinefamily

Advertising disclosure: We may receive compensation for some of the links in our stories. Thank you for supporting LA Weekly and our advertisers.