The USGA recommended method for determining a club's most improved player at the end of a season or year is as follows:
Add 12* to the player's Handicap Index at the start of the season. This is value A.
Add 12 to the player's Handicap Index at the end of the season. This is value B.
Divide value A by value B, calculating to three decimal places. This is the improvement factor. The player with the highest improvement factor should receive the most improved player award.