This is an issue that bothers a lot of golfers as they ponder why they can seemingly hit the ball so well on the range but not be able to convert this to the golf course. There are several factors that contribute to this which mainly boils down to insufficient preparation when venturing out to the course especially suiting up for competition golf. Some of the reasons for bad performance include:
The necessity of having correct alignment when on the course.
The realisation that the environment is totally different including the distraction and anxiety of playing with other people.
The feeling of wanting to score well.
Hazards including water, bunkers and other obstacles on the course.
High expectations especially if feeling though you are hitting it well on the range.
The pressure of competition.