Just played a round where I scored 42 on the back and 45 on the front. I played better on the front 9 based upon the statistics, but the odds were stacked against me. In all 3 strokes, there was some unfortunate situation that cost me those strokes. There were more than 3. I was playing pretty well, but: I caught a sprinkler head on the fringe of one hole that bounce the ball away from the green; a drive hit the 150 yard maker and bounced off to the side; a small wind blew a leaf or something that distracted me on the back swing of yet another drive; I slipped on a drive on the second hole because there was a little mud puddle in the tee box and the grass holding it together and tore loose on my back swing.
Towards the end of the round I was goofing around a bit, and worm burned a drive on the 18th trying to drive above trees and used a more exaggerated reverse-K stance. I hit some pretty decent drives, but my short game was bad in the back. In one case, I just got under the ball from only 50 yards away with my LW.
I was making sloppy reads with the putter. Front 9 putting saved me with only 14 putts, the back 9 had 18 putts. This is a pretty massive example, but I am not exactly a seasoned golfer and apparently do not know how to putt when I am tired.