Sentry Tournament of Champions: Inside the numbers as stars fall short

As defending champion, Dustin Johnson was expected to contend, so his 277 total, eight strokes off the lead and nine behind his 2018 winning score, was a letdown. That letdown was exacerbated by the fact that Kapalua played more than a full stroke easier this year than in 2018.

The first explanation is simply that golfers are not robots, however much Bryson deChambeau wishes it were otherwise. They have good weeks and less good weeks, and that includes Johnson.

In his case, the precision lapses generally applied to his work from the fairways or, to the extent it exists at Kapalua, the rough. During 2018, Johnson averaged a gain of more than eight-tenths of a stroke approaching the greens, a skill that put him nearly one full standard deviation ahead of his competitors.

At Kapalua, however, his play approaching the greens cost him about a fifth of a stroke per round. Among those finishing in the top six, the next worst performance from the fairways was McIlroy…and even he gained one-third of a stroke per round in that area.

In short, Johnson’s fairway play handicapped him by comparison with his fellow contenders to an extent that even his substantial skills in other areas could not offset.