Calculating handicap index increases/decreases | Golf Monthly

Score Differentials should retain two decimal places in order for the sum of eight of them, divided by eight is accurate to one decimal place.
Each Score differential has a positive or negative error or tolerance due to rounding to one decimal place.

There must always be, at any given time, a small percentage of players whose HI is "wrong" by one decimal place.
A small percentage of these will be tipped over the borderline to a "wrong" Playing Handicap.

All this could have been greatly avoided if Score Differentials had been kept to two decimal places.