Winners on Tour aren't only highly skilled; they have the ability to string together great rounds in a single event. Still, three great rounds followed by a clunker might earn you a rep as someone who can't close the deal. A player's "streakiness" counts for a lot, but in order to win, he's got to be what you might call streaky hot.
I measure the streakiness of a player by comparing his wins with how many times he would have won if he weren't streaky at all. Think of "not streaky" as picking a score at random from a player's scores for the season. "Not streaky" means that shooting, say, a 65 or a 78 has no influence on whether the next score is better or worse than a player's average score. (To account for the difficulty of a course, I use Strokes Gained versus the field, rather than round scores.) For each tournament a player entered, I simulate 50,000 outcomes of his "not streaky" play and compute the fraction of times he would have won. I call this his "non-streaky expected wins." If a player has more actual wins than non-streaky expected wins, then he's not streaky; he's just good at bunching great rounds together.
On the Tour from 2013 through 2016, the streakiest player was Jimmy Walker, the reigning PGA champion. He has won six times in that four-year period, but the "non-streaky" Walker was expected to win only 2.9 times. Put another way, his streakiness added 3.1 wins. In that same stretch, Patrick Reed's streakiness added 2.5 wins, Bubba Watson's added 2.4 wins, and Jason Day's added 2.2 wins.
On the opposite end of the spectrum, Keegan Bradley was winless from 2013 through 2016, but even a "non-streaky" Bradley was expected to win 2.0 times. His "anti-streakiness"—that is, his tendency to follow low rounds with high rounds—cost him about two wins. In that same span, anti-streakiness cost both Sergio Garcia and Jim Furyk 1.7 wins.
Pros work hard to put together great rounds. For most of us weekend players, it's about putting together a sequence of good holes. If, on any given Sunday, you can be streaky hot by matching or bettering your average score on most of your 18 holes, you'll likely shoot the best round of your life.