By The Book

"Defy convention"

—Diary entry of Luke Donald, dated April 6, 2011, on the eve of the Masters

It is a simple black binder, stuffed with a daily calendar the likes of which can be purchased for a couple of bucks. What makes the binder priceless is the hard-earned knowledge it contains and the self-belief that is etched onto the pages in tiny, tidy handwriting. Luke Donald calls it his performance diary. Every evening he writes down three goals for the next day. Some are specific—on Tuesday night of Masters week he scribbled "Win the Par-3 tournament," which in fact he did the following afternoon. Some are aspirational, like "Show confidence in body language," which he reminded himself to do in the middle of his spectacular run to victory at the Match Play Championship in February. Some are technical, such as when he riffed on a recent practice putting session on Saturday evening at the Heritage on Hilton Head, when he was the 54-hole leader: "More towards target on thru stroke, more acceleration to ball. Better strike kept better line."

At day's end Donald totals up how much time he spent working on his game and his fitness and writes down three conclusions, quantifying his work in statistics (22 putts for the final round of the Masters!) or observations ("Great driving, gritty comeback after double bogey on 2," from Saturday at Hilton Head.) There is even room for a little gloating and the occasional touch of hyperbole. After winning the Masters Par-3, Donald wrote, "Set my mind to it and happened. One down one to go."

Hogan dug the secrets of the game out of the dirt; Donald, 33, is using a ballpoint pen to maximize his performance. The diary has helped turn a 5' 9", 160-pound Englishman with a surgically repaired left wrist into arguably the best player in the world. Last year Donald ranked 177th in driving distance on the PGA Tour yet he piled up the second-most World Ranking points (behind only Graeme McDowell) as he finished third in the FedEx Cup standings and 15th in the Race to Dubai, banking more than $8.3 million worldwide. It was his first year working with self-styled performance coach Dave Alred. Donald had defied convention in seeking out Alred, who had virtually no background in golf but has worked closely with the English rugby team. (It was Donald's brother-in-law, Robert Ellis, who recommended Alred, largely because both live in Bristol.) Donald's stellar 2010 included another starring role at the Ryder Cup, but the season was not entirely satisfying for one simple reason: His only victory was at the B-list Madrid Masters.

Seeking that little edge that could turn more of his near misses into victories, Donald dropped out of sight for 11 weeks at season's end to better himself. The game may be increasingly dominated by brawny power players, but Donald is comfortable as an iconoclast and a throwback; he spent the winter seeking more precision in his ball striking, not in his length off the tee. By his side was not a self-promoting swing guru but the only man Donald has ever entrusted with his game, his soft-spoken college coach, Pat Goss, who still oversees the program at Northwestern. (Donald married a Chicago girl, the former Diane Antonopoulos, and instead of residing in tropical environs, they spend eight or nine months a year in the Chicago suburb of Northfield, the rare Tour couple to settle in a Northern clime.)

Over the winter Donald also embraced a more dynamic fitness routine. His swing and body in tip-top shape, Donald was only missing a cutthroat mental edge. With his posh accent, his oft-noted hobby of painting, his own wine label, that precious Polo wardrobe and all those Sunday disappointments, Donald may have been characterized as being a little too soft. Alred began hectoring him to think of himself as an assassin. (This echoes the nickname of pint-sized mid-century hero Paul Runyan, one of golf's great giant killers: Little Poison.) Says Alred, "What's the mentality of the assassin? One shot, one kill. There's a little bit of evil in him, but he's ice-cold, calm and precise. It's a perfect game face for Luke and his personality."

Donald missed the cut in his 2011 debut but has been slaying the opposition ever since, with a current streak of six consecutive top 10 finishes. His breakthrough at the Match Play was followed by a rousing tie for fourth at the Masters and a scrappy playoff loss at Hilton Head, where Donald battled fiercely on Sunday despite struggling with his swing. Having ascended to third in the World Ranking he is a favorite at next week's Players Championship, and based on his finish there are a handful of scenarios that could propel him to No. 1. Whenever he gets there—and it is increasingly a question of when, not if—the achievement will be all the more satisfying because Donald has achieved it in his own unique way.

"Love being great."

—APRIL 23, AS DONALD HELD THE 54-HOLE LEAD AT THE HERITAGE