Nothing is too complicated with Bubba Watson. The philosophy is a simple one: you hit the ball, go find it, hit it again. Sooner or later, you putt it into the hole; and you start again. In the second round of this 78th edition of the US Masters here at Augusta National, Watson - the left-hander who first showcased his wizardry in claiming a green jacket in 2012 - was up to his tricks again.

Watson took 68 strokes which, in itself, impressed; but hardly touched the spectacular. Yet, there was more to it. The magic, in its entirety, was reserved for a back nine that took in Amen Corner and, in coming home in 32, fuelled by a run of five successive birdies from the 12th, Watson reached the midpoint with a 36-holes total of 137 that left him three shots clear of closest challenger John Senden, with Thomas Bjorn and Jonas Blixt among those a stroke further back.

On a day of glorious sunshine, there were however dark clouds for some: Phil Mickelson, who has prowled this landscape with an owner’s mentality for the best part of two decades, with three wins and 14 top-10s on his CV, missed the cut; while that pain was felt elsewhere as Sergio Garcia, Ernie Els, Luke Donald, Dustin Johnson and Keegan Bradley were others to miss out.

“It’s not science here. It’s try to hit the greens and, if you’re hitting the greens, that means you’re obviously hitting your tee shots well,” said Watson of a philosophy that, for most, is easier said than done. In fairness to him, Watson executed his game plan to near perfection.

Early on in his round, Watson could have been excused for feeling some frustration when it seemed as if he had a razor blade rather than a putter in his hand. Time and time again, he shaved the hole with birdie opportunities. But he kept his cool, was calm and bided his time.

And, eventually, that putter got hot. “After nine years of missing all of them, I’m starting to make a few,” quipped Watson, who revealed he had recently changed his putter - going to a slightly longer shafted, multi-balanced model - in an attempt to avail of his height and athleticism. It’s an athletic putting stroke now instead of me trying to guide the ball in the hole. My whole golf game is based off of feel and I guess I’m athletic, so now I’m just trying to change my putt to do that.”

When the putts started to roll in on the 12th, there was no stopping him. “It’s one of those (stretches) where you’re not focused on what you’re doing. You don’t know that you’re making all these birdies, you’re focused one shot at a time. At Augusta, that’s what you have to do.”

The run was quite sensational: on the iconic par three 12th, he hit his tee shot to two feet; on the par five 13th, he hit a seven-iron approach and two-putted; on the 14th, he rolled in a 30 footer to keep the momentum going; on the 15th, he hit a five-iron approach and two-putted; and on the 16th, he hit a nine-iron tee-shot and rolled in the putt.

Of them all, the putt on the 14th was huge. And he got a break of sorts. Sergio Garcia missed the green with his approach and chipped, barely missing Watson’s ball marker, but enabling Watson to watch the Spaniard’s ball checked and rolled on breaking some 15 feet on its roll. “For me having that putt on the same line, I knew where to aim it, what the speed was. It was a lot different than what I was thinking,” admitted Watson. “Then, somehow, it went in . . . . without Sergio’s chip, I probably would have three-putted it.”

Watson has returned rejuvenated this time, a contrast to a year ago when, as defending champion, he was sucked into worrying about the Champions Dinner and his responsibility as a defending champion. “It drains you a lot more than you know. As soon as you win, you get a green jacket on you. Every sponsor that you have, every company that you represent, they want a piece of your time. Yellow flags? I’ve seen enough of those, I really don’t want to sign too many more of those yellow flags. I think I’ve signed every one since 2012.

“I do everything my way. I learned the game my way. I figured it out my way. So, it just takes a little bit longer with the mental focus and drive to get back to where I am,” added Watson.

Today’s run for home on the back nine - only marred by a closing bogey on the 18th where he missed a short putt - brought with it the midway lead. Nerves? “Yes, you’re nervous. And that’s why I’m keeping my head down, just to stay focused on what I’m doing, not to look at leader boards, just play golf . . . . it might turn out to be horrific, but at least I have a shot (at winning).”

Watson may have kept to a simple game and reaped the dividends, but the job is far from finished. As US Open champion Justin Rose observed, “there’s no give on this golf course; you can only take on one or two shots around the turn and the hole can start looking awfully small and those lakes can start to look awfully big. We saw it with Greg Norman in ‘96. it’s that kind of course and that’s why it is important to keep yourself in touch.”

Darren Clarke, who shot successive rounds of 74, made the cut for the first time since 2006 but Rory McIlroy - who suffered double-bogeys on the fourth and 10th - was battling to stay inside the cut line as he headed for home. Graeme McDowell was set to miss out on the weekend.