I graduated college with a minor in math, and I've actually used a decent amount of it in the real world. Like now, when I can tell you that the prefix "dodeca" means twelve rather than twenty (that's "icosa"), that the correct term for a competition with twenty-five events would be "icosikaipentathlon" (I looked it up), and that anyone who would seriously compete in that kind of competition would probably beat me up for pointing that out.
That probably includes brothers Jeremy and Mark (Mark Kelly and Steve Zissis, respectively, who really do look like they could be brothers). They had their own private version of the incorrectly-titled event when they were in high school over twenty years ago. It was all tied up with twelve wins each heading into the final event, but their father intervened and spoiled the outcome. Jeremy declared an outright win, while Mark claimed interference. Rather than simply call for a redo, they began a feud that would take them well into their thirties.
Now they're grown, and Mark's birthday is coming up. He's going with his wife Stephanie (Jennifer Lafleur) and son Hunter (Reid Williams) on their annual trip to visit his mother Alice (Julie Vorus). Jeremy wasn't invited, but shows up anyway and immediately throws down the gauntlet. Stephanie, worried about Mark's mental and physical well-being, tries to intervene, but Mark's competitive bug has been awakened and must be satisfied even if his family suffers as a result.
IMDB lists the film as a comedy, but that's a very generous classification. While it does try to be funny, there's nothing the movie that truly achieves that, and it is occasionally so awkward that it actually becomes uncomfortable. It also spends a good amount of time being serious, but most of those moments are predictable and therefore have no emotional impact.
It doesn't help that nearly all the characters are so completely despicable that we almost want bad things to happen to them. The decades-long animosity between the brothers is founded on a completely trivial issue that could have been easily addressed with a rematch of the final event. Stephanie may be inexplicably overbearing in her stance against the competition, but that doesn't excuse Mark's apparent willingness to throw away his marriage over it, nor Jeremy's berating him for the little hesitation he does show.
If there is anything about the film that is weaker than its story or characters, it would be the camera work. It appears that the camera operator is either unwilling or unable to provide a steady shot, but really loves zooming in and out, even at the cost of keeping the image in focus. You're not going to get seasick by watching the movie, but it's definitely noticeable.
Ultimately, The Do-Deca-Pentathlon is a complete disappointment. While it's not egregiously bad, it's a pretty long way from being good. There's no need to rush out and see this one.