Golf and psychology seem to go together and many a psychiatrist has been visited by a golfer regardless of their competence. I knew of one well known player who when under intense pressure went to what he called the "no mistakes swing" which he had in his repertoire -- a simple, reliable type of swing that he could call upon when he was in contention with a few holes to go. This swing wouldn't do anything fancy and wouldn't hit the ball as far as normal, but it was a repeating swing that would put his ball somewhere in the fairway or on the green.
The psychological aspect here is that he had this comforting thought process whereby, when things got tight, he had this to fall back on. The golfing area in our brains is a fragile domain that is terribly susceptible to suggestion. Golfers are gullible.
We have all played with people who would try to talk you into losing. They'll stand on the tee with an innocent expression and say, "look how tight out of bounds is on the left. I hope l don't hit it over there." Or they might come up with, "that's an interesting change you've made in your backswing". Or the old remark of whether you breath in or out on your backswing?
These remarks seldom bother an experienced player as it's a clear indication that the person making these remarks is extremely insecure. Playing this game that we all love makes you learn a form of meditation during the hours we're on the course, you learn to focus on the game and clean your mind of worrisome thoughts.
Out of bounds: Golf has probably kept more people sane than psychiatrists have.