In golf a birdie is a score that is one shot less than the expected typical score (`par') on a

given hole. Typically par for a hole is 4 shots, so that taking three shots to complete a hole

is a birdie. Birdies are good. Scoring a par (4 shots, in our example) is the expected score

and is the modal outcome for a professional golfer. A professional golfer with a birdie putt

(i.e. a putt that will score a birdie if it is sunk) starting 49.5 inches from the hole will make

the putt 83.5% of the time. A professional golfer with a par putt (i.e. a putt that will score

a par if it is sunk) starting from the exact same location will make the putt 88% of the time.

Explain this difference.