21, the story of math geeks who took Vegas for millions at blackjack, is slick, sexy, compulsive watching. It is difficult not to dream about doing it yourself.

Yet it is still a jolt when co-stars Kate Bosworth and Jim Sturgess lead a gambling tutorial on the DVD. They show how to count cards and increase your odds of winning. You do not have to be a genius to pull it off, but you still need a head for numbers that most people lack.

21 arrived this week in several options, primarily a two-disc Deluxe Edition that contains that cranium-cracking tutorial, plus droll comments from Kevin Spacey, the film's co-producer and best actor. He plays the cynical math prof who recruits a student gambling team.

This is based on a true story of MIT math wizards who wrapped studies in Boston on Fridays and jetted to Vegas for blackjack blowouts. Writer Ben Mezrich turned their saga into a book.

One of the real geeks is briefly interviewed on the DVD. More from him would have been great. He is merely a teaser. The paradox is that 21 plays as a fiction, in part because director Robert Luketic constructs it like a spin-off of the Ocean's series. Every scene, emotional beat and thrill is contructed by formula.

On the deluxe edition, Luketic does a commentary. Other extras include a tour of "the good life" of luxury goods that appeal to flush Vegas players. There is also a digital copy of 21 for uploading. It is Mac-phobic, working only for PCs and PSP machines.

Emotional Arithmetic

Palo Barzman's elegant Emotional Arithmetic, which debuted this week on widescreen-only DVD, lives far from Vegas. Instead, it is a drama about people gambling with the lingering spectre of the Holocaust.

Set in Quebec's Eastern Townships in 1985, and based on Matt Cohen's novel, the film examines the lives of three people who survived a Nazi concentration camp together but took different paths in the aftermath. When they stage a reunion, memories spin them out of control.

Yet the film itself is very much in control. It is formal, sombre, methodical and exquisitely photographed. Barzman is not a sentimentalist. And he assembled a remarkable cast of Susan Sarandon, Gabriel Byrne, Max von Sydow, Christopher Plummer and Roy Dupuis.

They, and the filmmakers, are interviewed on the DVD extras. Although the sound quality varies, the insights are singular.

Penelope

Modern fairy tales are difficult to construct with the right balance of whimsy, grace and Grimm-like metaphor. Mark Palansky's Penelope, which arrived on DVD last week with full and widescreen versions on the same disc, is slightly off kilter.

But I love the premise: A family curse dooms our heroine to be born with a pig nose. Christina Ricci pulls that off with aplomb and her makeup is stunning because -- like the story's theme -- her inner beauty gets you past snout-shock. James McAvoy's beguiling character is certainly enticed.

But the movie is messy, too concerned with slapstick asides such as the subplot involving a one-eyed, midget paparazzo. The balance is compromised, even if the movie is still an entertaining curiosity.

The DVD extras are minor, just one featurette with on-set interviews. Producer-actress Reese Witherspoon waxes poetic about the project.

Green Street Hooligans

English football fanatics -- extremists who use sporting events as an excuse for gang violence -- are complicated creatures. Lexi Alexander's Green Street Hooligans, which arrived on DVD last week in separate full and widescreen editions, gives their pathology a face and a voice.

Their world is opened up by a visiting Yank (excellent Elijah Wood) who is brought into a West Ham United "firm" by its charismatic but psychopathic leader (Charlie Hunnam). The emotional scenes are sometimes awkward, but the action is stunning and the story interesting for outsiders trying to understand what makes hooligans go mental.

The DVD has a routine making-of featurette. A doc on the real deal would have been more effective.