From the hallowed greens where the professionals compete to the common ground the duffers play, it's an affliction called the most wicked four-letter word in golf: yips. A mystery malady of flinches and twitches that make the "can't miss" putt un-makeable.
"It's embarrassing, it's frustrating, it's just awful," says Bob Jensen. "It's just a horrible feeling."
Jensen can drive a golf ball into the next time zone, but sink a two-foot putt? Don't bet your life on it.
An undiagnosed tremor in his right wrist has plagued Jensen's game for years. Dreading even the shortest putt, the flinch doesn't stop.
"It feels like it's right in there to me," says Jensen. "It's just like it tenses up and it's like a spasm almost."
Now, as CBS News Correspondent Bob McNamara reports, Minnesota's mecca of miracle medicine, the Mayo Clinic, is on the case.
Gathering 16 of America's worst "yippers," Mayo scientists wired them like lab rats with electrodes hooked to putters and monitors. They even took saliva samples, trying to learn whether yips are born of physical, psychological or neurological pressures that can go beyond golf.
"There are several other sports and occupations in which similar behavior occurs," says Mayo researcher Jay Smith.
Yips might be why Shaquille O'Neal can't make free throws and why classical musicians and surgeons have been stricken too.
"It always affects them in the muscles by which they earn their living and they are just devastated by it," says the Mayo Clinic's Dr. Ainsley Smith.
Some golf professionals say yips are more of a problem of the hands than the head.
"Good putters don't have bad technique," says one pro.
But that doesn't explain why some days Jensen's putting is smooth as silk, and the next wracked by the yips. That remains a medical mystery.