Don't stop here and continue reading as these kind of statistics are not boring at all !
Column2: club played.
The position of the ball indicated in column3 (tee, fairway, rough, sand, recovery shot or green) will have an influence on the average strokes of the PGA player (column4 of the table), the average of shots to putt the ball in the hole being be more important as the ball stands in the rough, in the sand or for a recovery shot (from the woods for example) than on the fairway.
The average strokes PGA reflected in column4 represents the data collected by the author of the book and will help to calculate the strokes a player would gain/lose against the pro.
The strokes gained (positive number) indicator or lost (negative number) compares the one stroke I need to move the ball forward to the average strokes needed by a PGA player to move the ball from the same position.
On the first hole, a drive from 498 yards would result in an average score of 4.41 strokes for a PGA professional while the next position from 260 yards would result in a score of 3.58. The difference of 0.83 strokes between these two numbers (see column6, 4.41-3.58=0.83) is then compared to the 1 stroke I need to move the ball to the same position.
I therefore only lost 0.17 strokes (0.83-1=-0.17) for that good drive on the fairway compared to a golf pro (column8).
The lost stroke of -0.17 is however minor and is a good result compared to the missed shot only moving the ball from 165 to 106 yards as the latter would result in 1 full stroke lost (-1.01, hole 1, column8 )!
These two examples solidly illustrate that a good/bad shot can now be mathematically measured !
Here below the conclusion of the entire round:
Based on the table above, the putting only represents 18% of the total lost strokes while the long game (drive + shots >165 yards) represents almost half of all lost strokes (47%). Working on the long game seems to be worth it as 10.2 stroked separates me from the pro on that part of the game ;-).
This table also indicates an excellent putting on the back nine as only 0.5 shot was lost compared to a pro which is a level pro putting !