How is it that some golfers follow up a great round of golf with a disastrous round the very next time they play?

What accounts for these variations in your level of play?
Well, the weather might change causing slightly different course conditions and you may be playing in a different group, but these changes will be similar for every golfer teeing off. What really affects consistency the most is your mindset…
Your thoughts or mental approach to competing each day. Consistent mental preparation leads to consistent performance, which applies to your pre-round prep and pre-shot routines. Some players go out on the golf course with the mindset: “Let’s see what today has in store for me.” Successful golfers prepare themselves mentally and put themselves in the proper mindset that has helped them perform successfully in the past.
Preparing yourself mentally is no different than warming up and taking practice swings. Your warm up serves
the purpose of helping your feel comfortable and ready for the first hole. If you are not physically prepared to
play, you can practically guarantee an inconsistent round. The same is true of mental preparation… Having
the most effective mindset for the day readies yourself for the challenges of the day.  Without mental preparation,
you have little hope of being consistent on the golf course. Since consistency is the hallmark of great golfers,
you must learn mental strategies to keep you from veering off course, so to speak.
One PGA golfer who has struggled with consistency is Rickie Fowler. Fowler’s performance seems to drop
off significantly after some of his best rounds, which is a phenomenon that happens to many golfers…
At the 117th U.S. Open, Fowler opened with a 65 on the first round to top the leader board. On Day 2, Fowler
had difficulty repeating his level of play from the previous day and shot a disappointing 73. Fowler rebounded
with a 4-under 68 during Saturday’s third round and entered the Final Round in fourth place and within striking
distance of the leader (2 strokes). With a consistent round, Fowler could have wrapped up his first Major title.
Instead, Fowler shot a 72 and finished tied for fifth…
Of course, you will have an occasional bad round or a few bad holes, but if you can keep your mental approach to each tournament and each shot consistent, then you improve your chances of performing more consistently over the course of a round or tournament.
How to improve your consistency on the golf course:
Consistent play is all about consistent mental preparation, both before a round of golf and during the round.
Develop a consistent preround routine. And a routine is not just about your physical warm up. It should be more about mental preparation:
Mental Preparation Includes:
1. Letting go of outcome expectations
2. Fueling your confidence
3. Preparing to trust your swing
4. Preround visualization

5. Using the butterflies to your advantage

Golfers Mental Edge CD