# Handicaps

This is an explanation of how we arrive at and apply handicaps.

Our scoring system, Compass, records both raw scores and handicaps for all sessions. Everyone thus has a *history*.

**Calculation**

Compass is able to look back into last season to gather sufficient data if we tell it we wish to consider the last however-many sessions. Compass can produce all the detail about who played with whom on which date and what score they got to back up its calculation which is:

**The highest and the lowest scores of however many results it found are dropped and the average of the rest gets subtracted from 50 to get a fix on how much better than "average" every player has been scoring.** (The scores of any session average out at 50%.)** This figure is further averaged with the player's old handicap to tie it in with previous history.**. This is known as the *"Tauranga Method"*

Some manual editing may now take place. Compass will not update player's handicaps if it finds less than five previous results. We go with what it says for nine or more results (the "greens") but need to research the "oranges" (six to eight) and the "reds" (zero to five). To do this we use the same parameters to produce a set of handicaps for other playing sessions. In cases where there is insufficient information for Compass to calculate a handicap directly for someone we can estimate an appropriate one by applying a correction to that player's handicap in some other session.

For instance: if Blair Fisher were to turn up for a Tuesday evening session he would not have enough history (it being unusual for him to play then) for Compass to base its calculation on. Blair would be a "red" for Tuesday evenings. But - we know he is a regular on Wednesdays where he has a handicap of , say, -8. Wednesdays are a much tougher school than Tuesday evenings so Blair should be handicapped even more. A comparison of the handicaps of those who play regularly on Wednesdays and Tuesday evenings gives us a figure by which to adjust for "reds" and "oranges". It could be as simple as Wednesday handicap minus 2 gives a good estimate for Tuesday handicap. Using such a formula we are able to assign handicaps to the "reds" and cross-check the handicaps calculated for the "oranges".

All this is followed up with a general eye-balling before the database is updated. It's quite a lot of work and we don't like to do it too often. Some other clubs assign a handicap for the whole season, whilst others just go with whatever Compass comes up with. We take more care as handicapping is such a minefield.

**Application**

We have traditionally used the system setting that applies the *average of the two handicaps* to the raw score when a pair plays together. Bob Fearn, the writer of Compass, recently provided the ability to apply a user-chosen percentage of the sum of the two handicaps. In this light, the method we currently use might be regarded as adding the handicaps of a pair and then taking 50% of the sum. We can now experiment with changing that to, say, 70% or 35% of the sum.

An example: Player A, who learnt only last year, has a handicap of +5.2 and plays with a more experienced player B who is on -3.4. In one session they get a raw score of 52.4%. Player C, another newbie, also has a handicap of +5.2 and plays with a classmate player D who is on +4.4. Their raw score is 44.6%. Under the default scheme the average of A and B's handicaps is applied to their raw score. Here 5.2 + (- 3.4) = 1.8 which averages to 0.9 ... this gets added to their raw score of 52.4 to produce a handicap score of 53.3%. The other pair's score is adjusted by half of 5.2 + 4.4 (= 4.8) to become 44.6 + 4.8 = 49.4%.

If we choose now to take 70% of the combined handicaps the results for the first pair will change to 52.4 + 70% of 1.8 = 52.4 + 1.3 or 53.7%. The second pair will get an adjusted score of 44.6 + 70% of 9.6 which comes to 44.6 + 6.7 = 51.3%. The handicaps, which have been produced fairly scientifically, are having a "widening" effect on the raw scores when applied with the higher factor of 70%.