As the cheers for Tiger Woods on the first tee gave way to the relative hush of patrons hoofing it to the green, a man behind the tee box turned to his wife and said, "I didn't hear anybody call Tiger a cheater."

Woods came into his 19th Masters with his body sound, his personal life settled and his putting stroke sharp. Just when all the wrinkles seemingly had been smoothed out in his crazy quilt of a life, controversy ruffled the calm.

Instead of concentrating on his pursuit of his 15th major championship, Woods awoke Saturday having to defend himself against a rules violation he committed in the second round.

Granted a reprieve from the tournament rules officials that came wrapped in a two-stroke penalty, Woods got back the two strokes in his third-round 70 and was tied for seventh with Tim Clark, at 3-under 213. They are four strokes behind the leaders, Brandt Snedeker and Angel Cabrera.

Woods has never won the Masters from behind, having held at least a share of the lead in his four victories.

"It started off obviously different," Woods said, referring to his day, "but I'm right there in the ballgame." Woods kept his post-round interview short, and could anybody blame him? His detailed description of his decision-making process on his drop at 15 on Friday got him tangled in controversy.

He was three strokes off the lead, held by Jason Day, at the completion of Friday's second round. On the 15th hole, Woods's third shot hit the flagstick and rolled off the green and into the water. After taking a one-stroke penalty, Woods dropped his ball in the fairway, a few feet behind his original divot to give himself a more comfortable distance to the pin for his wedge shot.

It was a good tactic - his ball stopped three feet from the pin - but it also violated Rule 26, which states that when choosing to drop near one's original divot, a golfer should play his ball "as nearly as possible" at the spot from which the first ball was played.

"You know, I wasn't even really thinking," Woods said Saturday. "I was still a little ticked at what happened and I was just trying to figure, 'OK, I need to take some yardage off this shot."' He added: "Evidently, it was pretty obvious I didn't drop it in the right spot."

Before Woods finished his second round, a television viewer texted a Masters rules official to call attention to the infraction. The rules committee, led by Fred Ridley, reviewed Woods' drop and saw nothing wrong.

In a television interview after his round, Woods said he purposely dropped the ball two yards behind his first divot, which raised some questions in Ridley's mind. Ridley spoke with Woods on the phone Friday night and met with him at the club Saturday morning.

After hearing Woods's explanation, Ridley said: "I told Tiger that in light of that information that we felt that he had, in fact, violated Rule 26 under the Rules of Golf and that he was going to have to be penalized."

Woods could have been disqualified for signing an incorrect scorecard. In allowing him to remain in the field, the Rules Committee invoked Rule 33-7, which allows a penalty of disqualification to be waived or modified in exceptional cases. The rule was instituted in 2011 to protect the players from retroactive disqualifications in instances in which armchair rules officials called in from home, as happened Friday, to report incidental violations that can be picked up on high-definition telecasts, like touching a twig on a backswing or a ball oscillating on the green.

"If it was done a year or two ago, whatever, I wouldn't have the opportunity to play," Woods said. "But the rules have changed, and under the Rules of Golf I was able to play."

The committee's decision not to disqualify Woods, who has 77 tour wins, for hitting his ball from the wrong place reinforced how the Rules of Golf, once as black and white as records on a page, have grown blurry. From the definition of a legal putting stroke to the enforcement of slow play, there has been confusion about the way to interpret and apply the rules.

On Friday, Guan Tianlang, a 14-year-old amateur from China, became the only known player in Masters history to be assessed a one-stroke penalty for slow play, which is endemic on the tour. Many players in the field wondered why Guan was singled out when some professionals routinely play with great deliberation and are never penalised.

On Saturday, Adam Scott, with a 69, and Tim Clark, with a 67, moved into the top seven using long putters that they anchor, a stroke that the US Golf Association and the R&A have proposed banning.

Ridley said that Augusta National officials did not consider disqualifying Woods on Saturday because it would have been "grossly unfair" to do so when officials had not talked to him about the drop before he signed his scorecard Friday.

Asked if he was concerned with the perception that Woods might have received preferential treatment as the world's top-ranked player, Ridley said: "I can't really control what the perception might or might not be. All I can say is that unequivocally this tournament is about integrity. If this had been John Smith from wherever, he would have gotten the same ruling, because again, it is the right ruling under these circumstances."

It was the second time this year that Woods had been penalised for an illegal drop. In the second round of his season opener in Abu Dhabi, he missed the cut after taking a two-stroke penalty for wrongly taking a free drop.

David Duval, a former world number one, was among the people who took to Twitter to say Woods ought to disqualify himself. "I think he should WD," Duval wrote. "He took a drop to gain an advantage."

Others, like Graeme McDowell, the 2010 US Open champion, took a different view. "Take the fact that it was Tiger out of the equation and it is a fair ruling," he said. "Since it is him, the debate begins about TV ratings, etc., etc."

What did Woods think? "I don't know," he said. "Under the Rules of Golf, I can play."