The Course Handicap is used in calculations for a Playing Handicap which is used for competition purposes only and changes depending on the format of play. The most important aspects of Playing Handicap to remember are:
1) It is only used for competition purposes
2) It ensures equity to calculate competition results
3) Golfers do not need to calculate it - the competition software does it for you
4) It is a mandatory percentage allowance that must be implemented in competition play
To calculate your Playing Handicap for a competitive round you need just one calculation:
Course Handicap x Handicap Allowance = Playing Handicap
i.e. Individual Medals and Stablefords - Handicap Allowance is 95%
Fourballs - Handicap Allowance is 90%
Foursomes - Handicap Allowance is 50% of the combined Course Handicap
Greensomes - Handicap Allowance is 60% of the lower Course Handicap plus 40% of the higher Course Handicap (then rounded up or down to a whole number)