Heroes of the Zeroes is Nick Rogers’ daily, alphabetical look back at the 365 best films of 2000 to 2009.

Dating-compatibility tests offer false security, suggesting easily cracked codes to avoid broken hearts. (Besides, they trivialize a communication constant: People know when to lie, and how lightly.) Even for those with shared interests, successful courtship rests upon gathering, testing, analyzing and agonizing over emotional intelligence.

When it comes to sorting out where we stand with someone early on, we’re all spies. Writer-director Tony Gilroy realized that romance done right involves invigorating risk, and 2009’s Duplicity offered a bracing, beguiling shell game of behavior to go with its light shenanigans.

Julia Roberts and Clive Owen crackled as corporate-world spies with a history that’s definitely sexual and possibly romantic, trading blows in a war between personal-hygiene product mavens (Tom Wilkinson and Paul Giamatti, character-actor emeriti working their magic of aggressive animosity).

Describing the plot would diminish delicious developments and double-crosses, as satisfyingly hearty as a sip of scotch. They complement James Newton Howard’s plucky pizzicato score and a swanky travelogue that allows location shoots — Dubai, London, Miami, Rome, New York, Zurich, Cleveland and, uh, Dunwoody, Ga. — to soak in.

Avoiding obvious vanity or drippy sentimentalism, Gilroy instead focuses on fascinating minutiae of temptations, tendencies, tricks and tells. Pattern analysis has rarely been so involving, whether it’s a running gag about frozen-pizza competition or passionate disclosures between people constantly listening for the flick of the lighter that could burn them.

Duplicity offered acute, rather than cute, romance, tackling titillation that comes with figuring someone out through trust … or a lack thereof.