You may wonder why I've just backed away from my putt. Just as what happened to Jim Furyk at the Heritage earlier in the year, it's happened to me here too.

I just what to explain a little bit about exactly the rule, and why Jim Furyk didn't actually get a penalty shot - but why it did affect his mind on that putt. 

So what happened? Jim came into his putt to roll it up the slope onto the green. As he took his stance and placed his putter down behind the ball, Jim thought that his ball moved. That's when he backed away and called in for a referee. 

During that discussion, the referee wanted to ascertain whether that ball had moved from its original spot. Jim Furyk wasn't particularly sure whether the ball had returned to its original spot or had still moved away from it. Because the referee and Jim had both thought that in this circumstance, the ball was deemed to be back on its original spot, there was no penalty and Jim continued.

Quite clearly it had affected his mindset for that round, and he went on to four-putt the green unfortunately. 
If, for example, that ball had rolled away from its original spot, and the player had taken his stance as we saw with Jim, then he would have incurred a one stroke penalty.

The important bit here is that you must then replace the ball to its original spot before you continue. If you fail to do so, you will incur another stroke penalty for playing from the wrong position.

So let me just recap. If you take your stance and place your putter behind the ball, and it oscillates - so it moves, and moves back to its original spot, there is no penalty. If the ball moves and doesn't return to its original spot, there is a one shot penalty and you must replace the ball to the original spot before continuing.