How to turn a golf index into a handicap

Never ones to make things easy, the French have a handicap system that requires a degree in mathematics. 
Here's how it works. Each golf course is graded according to its degree of difficulty. This grading is called the slope. However, there is a different slope according to which tee you are playing from. Add to this the fact that the slope is different for men and women even from the same tees.

So for example at Pallanne the slope from the blue tees  is 132 for men and 138 for women. The average slope of all the golf courses is 113, so you can see that Pallanne is graded as quite a difficult course even from the blue tees.

Now, as well as a slope there is the SSS — the Standard Scratch Score. As its name implies this is the average score that scratch players are expected to achieve. This also changes depending on whether the player is a man or a woman. Again, using the blue tees at Pallanne as an example, the SSS for men is 70.8 whereas for women it is 76.9.

So how do we work out the handicap if we have a golfer's index?

Here is the formula:

Multiply the index by the relevant slope then divide by 113 then add the SSS and subtract 72.

Here is an example using the slope and SSS for the Pallanne blue tees and my own golf index:

11.9  multiplied by 132 divided by 113 + 70.8 minus 72

which gives a handicap for me off the blue tees of 12.7. Simple !