Golf has for a very long time struggled with coming up with a way to measure performance. Traditional golf statistics such as fairways hit, greens hit and other similar variables do a very poor job of actually measuring performance in a way produces accurate results since it is not clear what exactly they are measuring.
Traditional golf statistics such as fairways hit, greens hit and other similar variables do a very poor job of actually measuring performance in a way produces accurate results since it is not clear what exactly they are measuring.
A golfer that hits tee shots into the trees have a very tough time getting a good ‘greens hit in regulation’ percentage, but despite this we look at greens hit as a proxy for overall approach shot performance. A golfer that misses every green but has a great chipping day and chips every shot to 1 foot can have 18 putts in an entire round of golf which sounds amazing, but it would merely be an average putting day since everyone makes almost all 1-foot putts. Counting putts and greens hit doesn’t take into account the distance from which the shot was hit, and this is the key to understanding the Strokes Gained concept.
Strokes Gained can sometimes be a difficult concept to wrap your head around. By nature, it’s a mathematical concept that doesn’t come intuitively to golfers and coaches in the same way as counting greens and fairways hit does.
It all starts with collecting the proper information about your performances on the golf course. The PGA Tour has been doing this since the early 2000s, even before they knew what to do with the information they were collecting. On Tour, each individual shot hit during a tournament goes into a big database, and from all the millions of shots in the database, you can create a table of the total number of strokes it takes for an average tour player to hole out from each distance and lie. As you are playing a round of golf, you are constantly moving the ball from one distance and lie to another distance and lie, and it is this relationship that is now being measured, how big the difference is between the ‘strokes to hole’ from the origin and the result of a shot.
Every shot you are faced with on the golf course can be expressed as having an expected score.
In essence, what you need to remember about Strokes Gained is that it deals with ‘Expected Score’ from each distance and lie. Explained in a different way: every shot you are faced with on the golf course can be expressed as having an expected score attached to it, the more difficult the shot the higher the expected score and vice versa. Here are a few examples:
Example 1: You play a hole that is 400 yards long. The expected score from that distance for a tour player is 3.99 meaning that it takes an average tour player 3.99 strokes to finish an average hole that is 400 yards long from the tee.
So far so good!
Now, the player hits a beautiful drive, 300 yards in the middle of the fairway so that the player now only has 100 yards to the hole from the fairway. This distance and lie has a new expected score associated with it which is 2.8, meaning that from this distance and lie, an average tour player, from 100 yards from the fairway, finishes the hole on average in 2.8 strokes.
Now we have the two pieces of information needed to calculate the Strokes Gained Value for shot 1 according to the following formula: [Shot 1 expected score] – [Shot 2 expected score] – 1 (because it took you 1 stroke to get there) = 3.99-2.8-1 =0.19. The player gained 0.19 strokes in relation to an average tour player on shot 1.
[shot 1 expected score] – [shot 2 expected score] – 1 = Strokes Gained for shot 1
If a player instead had hit the ball into the rough, we would use the expected score value from that specific distance and lie, and it would generate a different result, hence this calculation is catching the nuances of players’ performances in a way that traditional golf stats can’t do.
Strokes Gained is catching the nuances of players’ performances in a way that traditional golf stats can’t do.
We then go ahead and do these calculations for every shot the player hits during a round, and we can then categorize the player’s shots into a variety of different shot distances to really dig deep into analyzing the player’s performance.