Difference of Handicap Index vs Course Handicap

Difference Between Handicap Index and Course Handicap

When viewing your scorecard or schedule, the handicap might not match what's in the player list because your league is set to calculate a Handicap Index for a player, which is based on the rating/slope for the tee box the player is playing. When you do that, your Handicap Index is converted to a Course Handicap for the round.

Your index is a portable number that represents your demonstrated ability - but when it comes time to tee it up, that number is converted to a Course Handicap, which accounts for the difficulty of the course and tees played. 

Handicap Index vs Course Handicap Example

Why is this calculation done?

It's done because your "index" is not a measure of ability for any specific course.  It's an objective measure of a player's ability no matter what course they play, or which tee boxes they play from.

To show how and why this works this way, let's take an example of two players who always play different tees, and they each shoot 80, 20 rounds in a row. Their calculated index, which takes the best 8 out of 20 differentials (or whatever you set Golf League Tracker to) would be as follows:

This should make sense. Bob played the harder tees, shot the same score as Chris, therefore his index should be lower. It should be lower because an "80" from the Blue tees is a "better score" than an "80" from the White tees.

Now let's say Bob and Chris were to play a match. Again, Bob is going to play the Blue tees, and Chris the white tees. If we used the "index" value it wouldn't be fair to Bob, as he would be giving Chris 7 strokes, even though they shoot the SAME SCORE each time they play. So what do you do? You convert the Index back to a Course Handicap based on the tees they are playing.

The Formula

The formula for converting a player's Handicap Index to a Course Handicap is:

Course Handicap = (Handicap Index * Slope / 113) + Course Rating - Par

Then the course handicap is rounded to the nearest whole number

So Bob would be: 

CH = (10.4 * 121 / 113) + 68.9 - 72 = 8 (we round to the nearest whole number)

Chris would be:

CH = (17.6 * 109 / 109) + 63.0 - 72 = 8

So you might ask yourself why go through this when we could use the player's score relative to par and come up with the same number? That only works if these two players always play the same course, or in the case of a 9 hole league, always play the same side (and the same number of times), and each play the same tee box every time. But what happens if they go to the course across town, which is a more difficult course, or in the case of a 9 hole league instead of playing the front 9, they play the back 9, which is harder or easier than the front?  What does that look like?

Travelling to a Different Course

Bob and Chris are going to the course across town. Again, Bob will play the Blue tees, and Chris the white, however the course rating and slope is different from their home course they normally play. So we must take each player's Index and convert it to a Course Handicap based on the tee box each will play. We take a look at the scorecard and find the info for each tee:

Blue: 72.1 / 130, par 72
White: 67.5 / 125, par 72

The first number with the decimal (the number which is closest to the "par" of the course) is the course rating, and the whole number is the slope. Let's plug in each player's info into the above formula to calculate a Course Handicap for them, like we did above:

So Bob would be: 

CH = (10.4 * 130 / 113) + 72.1 - 72 = 12

Chris would be:

CH = (17.6 * 125/ 113) + 67.4 - 72 = 15

In this example, Chris would now get 3 shots from Bob for their match. If playing match play, he would get 1 stroke on the 3 hardest holes.

As you can see, if we had only used PAR as the calculation for our handicap, we couldn't take into account the difficulty of each side/course and tee box the players are playing and it would result in an unfair number of strokes being given. By the way, this won't always favor Chris, as it completely depends upon the rating, slope, and par each player is playing from their respective tee box.