While they're not over yet, this year's National Football League playoffs have already produced one spectacle for the ages: the remarkable ability of Arizona Cardinals' wide receiver Larry Fitzgerald to pluck passes out of the sky.

As the Cardinals prepare to face Philadelphia in Sunday's NFC championship game, Mr. Fitzgerald's acrobatics are the talk of the NFL. They have also stirred up a mystery: in photographs, Mr. Fitzgerald can often be seen doing something almost unfathomable: making catches with his eyes closed. "I don't understand it myself," he says.

On paper, Mr. Fitzgerald is not an extraordinary athlete. He's not the tallest receiver in the NFL or the best leaper. His 40-yard-dash time of 4.63 seconds at the 2004 NFL scouting combine is mediocre for the position. To explain his 1,431 yards receiving this season and his ability to haul in footballs with one hand or hold on to them while being pounded by defenders, most analysts say he must have soft hands, great timing or excellent body positioning.

But after 20 years of studying the eyes of elite athletes, and after taking into account two unusual opportunities Mr. Fitzgerald had as a child, one prominent researcher believes his catching talent has less to do with his hands and feet than his eyes and brain. The two catalysts for Mr. Fitzgerald's success may, in fact, be his stint as a teenage ballboy for the Minnesota Vikings and the summer days he spent at his grandfather's optometry clinic.

Joan Vickers, a cognitive psychologist at the University of Calgary, studies the eye movements of elite hockey goaltenders, baseball hitters, and tennis and volleyball players by having them play while wearing special goggles equipped with cameras that film their eyes. After watching Mr. Fitzgerald's 166-yard performance against the Carolina Panthers last week on television, she believes his talent reflects a mastery of two cognitive skills she has observed -- one called "the quiet eye" and another known as "predictive control."