Handicap Explained

[hrc333]

This GoogleDoc has detailed handicap information:

http://spreadsheets.google.com/pub?key=0AlZcoDOQS8MHdElBQWRDYXltdy1SU25aN09sVW42LWc&hl=en&gid=3

- all players' current handicap (updated 12/16/12)
- the adjustment factors as described below
- example showing a player's handicap over the course of two seasons
- regression using three season's worth of data, showing that lower ranked players will have a better chance of cashing under the new system

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New System in effect for Summer 2010

The new system is designed so that

- it is easier for lower ranked players to cash
- bagging, intentional or otherwise, is non-productive

The new system mimics a stick golf handicap by throwing out a player's worst scores. Once a player has at least 15 weekly scores:

1) average the player's 10 best Relative scores out of his last 15 weeks, with the relative score defined as the player's raw score less the week's median score
2) multiply average in (a) by -90% = this is the player's handicap
3) your handicap does not reset at the beginning of a new season

For new players that have less than 15 total weeks played, there is a sliding adjustment scale for both the number of bad scores to throw out and the % multiplier. In addition, for players with less than 15 weeks, the handicap used to calculate the adjusted score will include the current round. For players over 15 weeks the adjusted score will use the handicap the player had before that round. These adjustments for new players were incorporated to offset the advantage a new player has with fewer scores in their handicap.

A new player can cash on their third round of play, as before. The payout structure is the same for the best adjusted scores of the week; the player(s) with the best raw score will always get at least $5.

It is now possible to have handicap scoring for the first two weeks of a season; however we will keep the tradition of having the first two weeks as raw score only. The new system has no effect on the season rankings; this remains as the average of all a player's Relative Scores. You must play half the weeklies to qualify for the season end prizes.


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Old System

Here is an explanation of the handicap system that was used from Summer 2007 through Winter 2009-10.  This is a combination of the old system we used to use and the system that Berkeley uses.  This attempts to solve the issues of both the different layouts being greater degree's of difficulty and the issue of allowing everyone, including beginners a chance to win.

Relative Score:
All scores in the weekly are relative to the Median Score for any given week.  The median score for a week is considered par for that week.  This means every week half the field will be under par and half the field will be over par.  Par is always the middle of the field.

Handicap:
This number will the the number of strokes added or subtracted from your your score.   Your handicap will be your mean relative score multiplied by a number determined by your Standard Deviation.  This means someone who intentionally sandbags a round  will lose much of the benefit they receive from a higher mean score by having a higher multiplier due to a higher standard deviation.

Your handicap will be established during your 3rd weekly.  
After the first 2 weeks of the season, you must have a handicap to cash.  If you do not yet have a handicap, then you may choose to not pay while establishing your handicap.  If you choose not to pay, you cannothit the ace pool.

STD Mean Over Par Mean Under Par
0-2 80.00 80.00
2-2.5 75.00 85.00
2.5-3 70.00 90.00
3-3.5 65.00 95.00
3.5-4 60.00 100.00
4-4.5 55.00 105.00
4.5 + 50.00 110.00


This means that each player will know how many strokes they receive as a handicap.  

Example:

Pro A
Mean -10
STD 2.1
Handicap: 8.5

Pro B
Mean -10
STD 4.2
Handicap 10.5

Beg A
Mean 25
STD 2.2
Handicap 17.5

Beg B
Mean 25
STD 5.6
Handicap 12.5

[uofc2003]

Can someone please provide an explanation that makes sense. I don't need to know how to calculate st. deviation, but what magical (hopefully mathematical) formula combines one's average and st. dev. to create one's handicap?

[Kevin]

Can someone please provide an explanation that makes sense. I don't need to know how to calculate st. deviation, but what magical (hopefully mathematical) formula combines one's average and st. dev. to create one's handicap?

James,

The handicap formula is Average(Relative Score to Par) * (-Multiplier %), where the Multiplier is derived from table above based on the Standard Deviation of all scores.

Walking through a detailed example:

The Median scores for weeks 1-5 are (57, 58, 58, 54, 56)
My scores for weeks 1-5 are (54, 59, 57, 47, 52)
Your scores for weeks 1-5 are (54, 55, 54, 54, 52)

My Average relative to par would be avg (-3, 1, -1, -7, -4) = -2.80
Your Average relative to par would be avg (-3, -3, -4, 0, -4) = -2.80

We have the same Average, and thus in the overall Summer standings e.g. would be listed as tied. However, because your scores are more consistent, you would have a less penalizing handicap:

My StDev = 3.03, so my handicap would be -2.80*-95% = 2.66
Your StDev = 1.64, so your handicap would be -2.80*-80% = 2.24

For Week 5, my adjusted score would be -4+2.66 = -1.34
For Week 5, your adjusted score would be -4+2.24 = -1.76

And you would finish ahead of me in the weekly standings. Hope that was clear.

[doublejack]

That was great, Kevin. Thanks. I've been needing a walk-through like that for some time.

[staffordlake]

I'm working on the Stafford Thursday weekly and find this all really interesting, but I question the use of a standard deviation in the handicapping.

Assuming that the purpose of a handicap is to make everything fair, in the example you provide, the person with the greater variability gets a higher handicap and a bigger advantage. So if those two people were to play against each other, every day for a year in a two person tournament, the person with the more consistent scores would have a lower handicap and would win less than 50% of the time, which is not fair. And if you have a scumbag who goes and adds some shots to his bad days, he will get a greater advantage from bagging.

So although standard deviations are a cool mathematical construct, I don't think they are appropriate in handicapping.

I think the United States Golf Association (USGA) has this figured out better. The stick golfers simply take the last 20 scores, take the 10 best, and base the handicap on the average of those 10 best scores. The only bagger that would gain an advantage would be the person willing to bag over 50% of their rounds.

Just my thoughts as I'm curious what other think.

[Kevin]

staffordlake,

The handicap system we have is the reverse of a normal stick golf handicap - the better players have a higher (positive) handicap, and the novice players have a lower, or even negative, handicap. The player with the more consistent scores would have a lower handicap, and would be penalized less, than an inconsistent player with the same overall score average.

Not saying our system is perfect, just want make clear that the Standard Deviation adjustment was put in place to discourage bagging, and does in fact penalize the inconsistent player.

re: USGA handicap - there is a course difficulty adjustment factored in as well, similar to how we are basing off the day's median score, which could be higher due to more difficult pin positions. Best 10/20 requires 20 rounds to get official handicap; to encourage new players I would recommend reducing # of rounds to establish their handicap if you go down this path - SFDC requires only 3 rounds.