Yips is a sudden and unexplained loss of ability to execute certain skills by experienced athletes
Most conceptualized in sports that has extremely short time performing the key move. It was named by a golfer but also discussed in cricket, archery, gymnastics. In golf the crucial part of the swing takes maybe half a second. The average score in a round of golf (which as far I can tell equals to a day of golfing) is 90 which means 90 swings. So in a day a golfer is playing for 45 seconds.
In golfing communities word yips is like a taboo. One shouldn’t mention it because people try not to remember about this mechanism.
Yips and psychology behind golf explained in this podcast
First article on Yips: “Once you had them you got them”