Many articles of classic menswear are derived from sport. The OCBD is one of them.
in the late 19th century, British polo players used buttons (among other things - pins, for instance) on the tips of their dress shirts of oxford cloth (itself invented in Scotland and named after the prestigious university) to prevent them from slapping their faces ruddy whilst in full gallop. Upon seeing this, John Brooks went back to the good ol' US of A and began producing them in masse. A style wasn't born, but instead reached a wider audience, worn mostly while not riding a horse. A modern-day example would be, oh, say, basketball shoes. Very unfortunate.
Despite its roots in UK play, the OCBD became largely American and stayed so for decades; to this day they are largely unseen in English offices. The Italians, however, embraced the OCBD and, in the eyes of many, perfected it. How? By focusing on the very thing that defines it: the collar.
Returning to the original style and construction, a proper OCBD collar has long points (not wimpy collars resembling uniforms), is soft and unlined (unlike the starchy numbers worn in town), and pleasantly wrinkle-prone. The result is the characteristic OCBD collar roll - a charmingly curved shape, one that is animate, ever-changing, alive. Therein lies the relaxed appeal of something otherwise associated with formality.