Rules of Golf
How long can you wait when your ball is sitting on the edge of the cup?
In many cases, the Rules of Golf are extremely specific. For example, a ball can't be any smaller than 1.680 inches (or 42.67 millimeters) in diameter and can't weigh more than 1.620 ounces.
In others? It gets a bit vague—and subject to more interpretation.
Let's say you've put a fabulous stroke on a long putt and your (conforming size and weight) ball rolls up and perches right on the edge of the cup. How long can you wait before you tap in—and make the obligatory complaint to your playing partner that that half-inch putt counted the same as the drive you piped right down the middle?
The answer is 10 seconds. Sort of.
According to Rule 13.3a, a player has 10 seconds to wait for his or her putt to drop from the lip—but that's after taking a "reasonable" amount of time to reach the hole. You (and your playing partners) are allowed to determine the "reasonable" part for yourselves—which means the bar might be different for you than, say, an Olympic sprinter.
That means you can't handle it like Si Woo Kim did at the RBC Heritage last year. After creeping a putt up onto the edge of the cup, he walked up and examined the ball from every which way for more than a minute before it eventually fell in the cup. Since it took more than 10 seconds to fall after he arrived at the hole, Kim had a stroke added to his score.