Woods explained the situation on Twitter on Saturday morning.

"At hole #15, I took a drop that I thought was correct and in accordance with the rules," Woods wrote. "I was unaware at that time I had violated any rules. I didn't know I had taken an incorrect drop prior to signing my scorecard. Subsequently, I met with the Masters Committee Saturday morning... and was advised they had reviewed the incident prior to the completion of my round. Their initial determination...

was that there was no violation, but they had additional concerns based on my post-round interview. After discussing the situation...

with them this morning, I was assessed a two-shot penalty. I understand and accept the penalty and respect the Committees' decision."

Before 2012, Woods would have been disqualified for signing an incorrect scorecard.

Under new rules enacted by the United States Golf Association and R&A in 2011, a player can have penalty strokes added afterward when facts were not reasonably presented at the time of scorecard signing.

"This is a logical and important step in our re-evalution of the impact of high-definition video on the game,'' said USGA executive director Mike Davis at the time the new rule was announced in August 2011. "We collectively believe that this revised decision addressed many video-related issues never contemplated by the Rules of Golf.''

Fred Ridley, former president of the USGA and the chairman of the Masters competition committees, detailed the timeline of events surrounding the penalty in a statement released Saturday morning.

"After being prompted by a television viewer, the Rules Committee reviewed a video of the shot while he was playing the 18th hole," Ridley said in the statement. "At that moment, based on the evidence, the committee determined he had complied with the rules.

"After he signed his scorecard, and in a television interview subsequent to the round, the player stated that he played further from the point than where he had played his third shot. Such action would constitute playing from the wrong place.

"The subsequent information provided by the player's interview after he had completed play warranted further review and discussion with him this morning. After meeting with the player, it was determined that he had violated Rule 26, and he was assessed a two-stroke penalty. The penalty of disqualification was waived by the committee under Rule 33 as the committee had previously reviewed the information and made it's intitial determination prior to the finish of the player's round.''

Ridley later said they had consulted with the USGA, which agreed on the decision not to disqualify Woods.

Woods learned of the brewing controversy when his agent notified him by phone early Saturday morning.

Mark Steinberg said he called Woods to discuss the situation, at which point the golfer quickly made arrangements to get to Augusta National and discuss the violation.

"He came in, didn't do it by phone, came in here and explained what happened yesterday,'' Steinberg said. "He was not doing any negotiating. He was coming in to explain himself. Whatever decision was going to be rendered, he was going to respectfully accept it. He abided by the rules of golf.''

Reaction was swift and all over the golf map as the story unfolded overnight and into Saturday morning.

Three-time Masters champion Nick Faldo said on the Golf Channel: "Tiger should really sit down and think about this and what it will leave on his legacy. Personally, I think this is dreadful. ... That was no intention to drop close to the divot.''

But current players were positive in their reaction, though defending champion Bubba Watson bristled at the idea a TV viewer can change the course of a tournament by calling in with their observations.

Watson, after shooting a third-round 70 to climb to 2 over, said unlike the TV viewer who raised the issue Friday with Masters officials, he wouldn't even know who to call if he saw someone breaking a rule.

"So I don't even know how these people get a number to call," Watson said. "And obviously they got more time on their hands than I do, because I don't know the number and I'm playing in the golf tournament."

Watson said he was glad Rule 33 was adjusted.

"It should protect us," Watson said. "The sad thing is the high-profile player gets the camera on him at all times. A guy could break a rule and not know he broke the rule. Like me today, there's no cameras on me today, everybody could care less what I was doing."

But Watson said TV viewers shouldn't be able to affect how players make rule decisions.

"So when somebody calls in like that, yeah, it shouldn't be that way, it shouldn't be allowed," Watson said. "Nobody calls in during a basketball game or a football game."

Fred Couples called the rule adjustment "a blessing for every golf pro in the world."

"We all know that we'll get the same ruling if it happens to one of us," said Couples, 1 shot back entering Saturday's round.

Graeme McDowell, who at 5 over missed the cut by 1 shot, tweeted Saturday morning that he agreed with the penalty.

"Take the fact that it was Tiger out of the equation and it is a fair ruling," McDowell posted to Twitter.

Hunter Mahan, who shot a second-round 82 and missed the cut at 14 over, also weighed in via Twitter.

"I like this ruling because he took an illegal drop but no official brought it to his attn," Mahan wrote.

Woods was 5-under par and tied for the lead when he played his third shot to the par-5 15th. He had 87 yards to the hole and saw his ball hit the flagstick and then roll back off the green and into the water.

Under Rule 26-1, Woods had three options at the yellow-staked (not lateral) hazard, which is a pond that fronts the green:

• He could have played from a designated drop area, which he chose not to do because he did not like the lie.

• He could drop the ball, keeping the point where it last crossed the margin of the water between the hole and the spot on which the ball would be dropped. Since the ball entered the water well left of Woods' position from the fairway, Woods did not choose this option – which would have allowed him to drop on a straight line as far back as he wanted.

• Or, he could return to the original spot from which he played, and drop "as nearly as possible,'' from where he played the third shot.

The question appeared to be whether Woods droped the ball as near as possible to his original spot. The ruling said no.

After the round, Woods said: "I went back to where I played it from, but I went 2yards further back and I took, tried to take two yards off the shot of what I felt I hit.''

Two yards was not close enough.

"Still not convinced he will play,'' said Woods' former coach, Hank Haney, on Twitter, suggesting that Woods might withdraw.

Woods also had an issue with an improper drop earlier this year at the Abu Dhabi HSBC Championship, where a two-stroke penalty caused him to miss the cut.

Woods mistakenly thought he could take relief from an imbedded lie on the fifth hole, and had even sought fellow player Martin Kaymer to ask his opinion. Kaymer agreed, so Woods took a drop.

But later a rules official determined that it was a sandy area, meaning Woods was not entitled to a drop; he should have played it or taken an unplayable lie, a one-stroke penalty.

Woods did not challenge the ruling afterward and the two-shot penalty was added to his score, meaning he went from one stroke inside the cut to missing by one stroke.