Interesting case: Long-time Amateur of 50 ranked rounds, best scores 39, 39, 40, 40, 6*41 are counting in (double for average calculation). Due to saturation, only scores better than 41/82 will move the average.
Strictly speaking of 9 hole rounds, each digit below 41 will drop the average by 0.2. That is, one 37/74 will do the job, as will 3*39/78 or 4*40/80.
Have fun from the longer tees and on "fast" greens! Keep in mind that the average calculation will be reset then.