THE grass is greener, the course is softer, but there’s a name high on the leader board that’s the same. A year after three-jacking away what would have been his first major championship, Dustin Johnson is in contention at another US Open.

It’s Groundhog Day at Oakmont.

Johnson shot 67-69 on Friday – playing 36 holes because of weather delays a day earlier – to take the early clubhouse lead at four under par. Andrew Landry is also four under but won’t play his second round until Saturday.

Now the question is what will Johnson do with that lead? Let’s examine:

How good were Johnson’s streaks of 27 holes without a bogey and 25 straight greens in regulation?

In 2011, Rory McIlroy played his first 35 holes without a dropped shot on his way to winning by eight at Congressional. That’s the highest total in the last 30 years, and Johnson is right behind it, though Johnson’s might be more impressive given the difficulty of the course and having done it in one day. As for his 25 straight greens in regulation, a streak that began on the third hole of the first round, no one at the USGA could find one better. Going back to the final round of last year’s Masters, where Johnson was in contention late into Sunday, he has hit 35 of his last 41 greens in regulation.

How big of an advantage is Johnson’s length at Oakmont?

In a word, well, big. The field averaged 259 metres off the tee through Friday. Johnson’s average? A whopping 290m. Given the severity of the greens at Oakmont, there’s a real difference with each less club a player hits into them. It’s not just about length, though. It’s imperative to hit fairways and Johnson has done that, too, hitting 20 of 28 so far. If he continues to drive it that well, he’ll be tough to beat.

Is Johnson’s putting good enough for him to win?

As well as he drove it and hit it with his irons – playing partner Sergio Garcia said Johnson was “awesome” – Johnson’s putting didn’t match up. Johnson missed eight putts from 15 feet and in, including three birdie chances from 10 feet or closer on Nos. 14, 17 and 18. “I felt like I hit good putts,” Johnson said. “It’s just tough. I felt like I left myself in good positions too. Just if you’re just a hair off, it doesn’t go in. … They’re going to go in eventually, but I made some nice putts too.”

Has Dustin gotten over the scar tissue of last year and other majors he has blown?

Check back on Sunday. That’s when it matters. The first two days have never been a problem for Johnson, who leads the US PGA Tour in first-round scoring and is third in second-round scoring. So far, so good this week. The real test is still to come. Johnson is 77th in third-round scoring and 57th in final-round scoring, with both numbers roughly two strokes higher.

In his last nine majors, Johnson is a cumulative 40 under the first two rounds, best of anyone by 15 strokes. In the third and fourth rounds, however, he is just two under, which ties for 49th best.

That said, Johnson has the mindset of a baseball closer, forgetting the game he blew the night before (or in this case the week before). Asked if last year’s three-putt on the final hole to lose at Chambers Bay still weighed on his mind or motivated him in any way, Johnson smiled and said simply, “What happened last year?”