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Jono
13th May 2005, 11:21 AM
Andy, which buttons ??
(h1-h2)/h1 x 100 ;)

Suffering from a bad case of insomnia, I typed this out last night … A bit of nit-picking, I know, but I believe the above formula favours the lower markers, especially those close to scratch handicap.

I know our resident math genius, Trung, has noted it already, but your equation, AndyP, for calculating improvement rating is somewhat faulty. What you are calculating is the handicap deduction as a percentage of the old handicap. So, if a 1 handicap got his handicap down to scratch, he'd get 100% improvement. Likewise, a 36 handicap who miraculously got his handicap down to scratch would get 100% improvement. The former only has to have a good round or two to get to scratch, but the latter would probably have to sell his soul to the devil in order to achieve a scratch handicap. Essentially, your rating system greatly favours the lower markers.

And what about those who have plus handicaps? Say you go from scratch to plus one? The calculator would say error because it can't divide by 0. Say you go from plus one to plus two? You would get a negative percentage.

There are two main problems using your equation to calculate improvement:

a) you are using a percentage … i.e. you are calculating a ratio. What you should be doing is multiplying the drop in handicap by a "difficulty multiplier". So you recognize that it is more difficult to drop shots as your handicap improves, but you don’t get ridiculous situations like the example above with the 1 and 36 handicap.

b) you are using the scratch handicap as the absolute zero. As you can see, once you reach scratch handicap, your equation breaks down. You need to set a lower mark as the absolute zero, recognizing that it is quite possible to drop one’s handicap into the plus range.

Here's my proposal for working out the "improvement" rating.

We need to make a couple of assumptions.

Assumption 1) What is the BEST possible handicap that one can have? I suppose if you are a machine, you can get birdie every hole and shoot 18 under par. What is the best handicap that a HUMAN can have on a course with ACR of 72? (i.e. average difficulty) Let's say plus 10. I think even Tiger would have difficulty averaging 10 under even on an easy course.

Assumption 2) What is the WORST possible handicap? Let's say 36.

Assumption 3) Using these two reference points (ie. 10 under par for best handicap and 36 over par for worst), we can work out a "difficulty multiplier". Let's say you start with 36 handicap. As you get closer and closer to the "perfect handicap" of plus 10, it gets harder and harder to drop a shot. And this increase in difficulty is not linear. The difficulty of lowering your handicap is INVERSELY proportional to how far your handicap is from the "perfect handicap". So, if your handicap is 36, lets say your difficulty multiplier is one. Let's say you HALVE your distance to the perfect handicap of plus 10. (36-(-10))/2 is 23. i.e. you are 23 away from plus 10 handicap which is a handicap of 13. The difficulty multiplier is now 2 (i.e. it is now twice as hard to drop a shot when you are 13 handicap than it was when you were 36). Lets say you halve your distance again ... (13-(-10))/2 is 11.5. i.e. your are 11.5 from plus 10 which is 1.5 handicap. The difficulty multiplier is now 4. i.e. it is twice as hard to drop a shot than it was at 13, and four times as hard as it was at 36.

Using this approach, we can come up with an equation to calculate the difficulty multiplier:

D (difficulty multiplier) is INVERSELY proportional to (your handicap - best possible handicap)

so D = k * 1/(your handicap - best possible handicap) where k is some constant.

For simplicity, we can let k = the number of strokes between the best possible handicap and the worst possible handicap. This way, we get D = 1 if your handicap is the worst possible handicap.

So D = (worst possible handicap-best possible handicap) / (your handicap - best possible handicap)

Let's use plus 10 as the best possible handicap and 36 as the worst.
I'll use H as "your handicap"

D = (36-(-10)/(H-(-10) = 46/(H+10)

So let's say your handicap is 36. Then your difficulty multiplier is 46/(36+10) which is 1.

Let's say your handicap is 13. Then your difficulty multiplier is 46/(13+10) which is 2.

Let's say your handicap is 5. Then your difficulty multiplier is 46/(5+10) which is approximately 3.

Let's say a 36 handicap, 13 handicap, and a 5 handicap all drop a shot in their handicap. The 36 handicap would multiply that shot by his D which is 1. So he would get an improvement rating of 1. The 13 handicap would multiply that shot by his D which is 2 and get an improvement rating of 2. 5 handicap would get an improvement rating of 3. So providing they all drop a shot, the 5 handicap would have the best improvement rating.

Now, theoretically, D should change for every shot you drop during the improvement period. Sort of like variable interest. You get interest on the interest. However, for simplicity's sake, let's use your AVERAGE handicap during the improvement period to calculate the difficulty multiplier.
So H = (h1+h2)/2

So if you started at 36 handicap and at the end of the period, you finished at 30. Then your average handicap would be 33. So H = 33.

Using this we can formulate an equation for the improvement rating.

I = improvement rating

I = drop in handicap * difficulty multiplier
I = (h1-h2) * D
= (h1-h2) * 46/(H+10)
= 46 * (h1-h2) / ((h1+h2)/2 + 10 )

Math geniuses like Trung, should be able to see instantly that as your handicap approaches the “perfect handicap” of plus 10 (i.e. H = -10), the difficulty multiplier D approaches infinity. When your handicap is the maximum possible (ie. 36) your difficulty multiplier is 1.

So the corollary of all this rambling is that the formula 46 * (h1-h2) / ((h1+h2)/2 + 10 ) gives us a much better estimation of your improvement in relation to other golfers, as opposed to the percentage formula (h1-h2)/h1 x 100. The latter favours the low markers too much.

And the other corollary is that I have too much spare time on my hands … :wink: :lol:

AndyP
13th May 2005, 11:47 AM
:smt119  :smt104  :smt103  :smt107
I'm speechless.  Way too much effort for something so minor.

So is this the formula that puts you near the top of the table? ;)

Congratulations to those who made it more than a third of the way through the above post. :mrgreen:

3oneday
13th May 2005, 11:48 AM
Jono,

Did you say something ??

:lol: :lol: :lol:

marcel
13th May 2005, 12:13 PM
And the other corollary is that I have too much spare time on my hands …  :wink:   :lol:

You got something on your hands alright.............or should that be the other way around

AndyP
13th May 2005, 12:50 PM
If you're going to change something, change the monet list winner. Alter it from total money to "dollars per appearance". Call it a strike rate if you like.
You didn't even try, 69. Where's the formula derivation?

3oneday
13th May 2005, 12:54 PM
You didn't even try, 69.  Where's the formula derivation?he has his hands in the right order, unlike Jono :shock:

:lol: :lol:

markTHEblake
13th May 2005, 01:22 PM
Are you a Dr or a Scientist? :)

I follow your logic but a couple of your assumptions is wrong.

Firstly is that the winner will be based on the most improved according to the stated formula. Nope, its just a guide.

Last year the voting panel (myself, Andyp and couple of others) as such looked at all the players and voted for Amanda based on a number of things, including effort. From memory she was 2nd according to the % formula.
The other person if i recall correctly had improved more % wise, but he had previously played on an even lower handicap, or something like that.

Now if anyone wants to be part of the voting panel all you gotta do is donate a trophy.


The former only has to have a good round or two to get to scratch, but the latter would probably have to sell his soul to the devil in order to achieve a scratch handicap.

to get from 1 to scratch is like pulling teeth, he has to have much more than 1 or 2 good rounds. More like 7 and no bad rounds.

for any golfer on 3.5 or less, to lose 1 stroke he must have 10 under his handicap - in 1 or 2 rounds, extremely unlikely.
Then he cant have any bad rounds, as he will go out .2 for those.

On the other hand a 36 marker could have 9 bad rounds and 1 good one. He might lose 4 strokes for the good one, and goes out .9 for the rest.

The low markers have to be extremely consistent to maintain their handicaps, and to improve them is an extreme effort. That is the reason you will see a large number of half decent weekend golfers that play off 4/5, becuase its very hard to break through that barrier of 3.5 (and i should know i tried for years - it cant be done!)

Virgal_Tracy
13th May 2005, 01:38 PM
While I agree with jono that this is favoured towards the low handicapper, and MTB I rspect your thoughts, can someone give me an asprin because my head hurts after trying to figure out the Doc's argument.

Stick with the percentage change and let those who make the decisions do what they do best (worst, whatever). Very few times will a B.O.G. or B & F be agreed upon by all.

Jono
13th May 2005, 02:02 PM
And the other corollary is that I have too much spare time on my hands …  :wink:   :lol:

You got something on your hands alright.............or should that be the other way around

Man ... Tough crowd, this Ozgolf bunch. You just gotta have one hand in your trouser pocket and you are called a w@nker ...

Tough crowd tonight, ladies and gents ... :lol:

Jono
13th May 2005, 02:12 PM
Ok I am now officially freaked out !  :shock:
Disturbing stuff.

If you're going to change something, change the monet list winner. Alter it from total money to "dollars per appearance". Call it a strike rate if you like.

Here you go ...

POTY = $$ * KK/(BLR*n)

POTY = points for player of the year award
$$ = total money won
KK = number of Krispy Kreme doughnuts you can eat in one sitting
BLR = number of bunker left & right at your home course
n = number of rounds you have played

I hope you find that equation less freakish ... :wink:

Jono
13th May 2005, 02:18 PM
MTB,

Ahhh ... at last ... someone who appreciates the beauty of logic ... 8)

Thanks for enlightening me on the magic barrier of 3.5 ... I wasn't aware of how the handicapping system changed when you reached this magic number. Hmmm ... now I understand why Pete is so fixated with getting down to 3 again ... 3oneday ... :lol:





Last year the voting panel (myself, Andyp and couple of others) as such looked at all the players and voted for Amanda based on a number of things, including effort.

Are you sure it wasn't because she is better looking than the other candidate? :wink:

andylo
13th May 2005, 02:23 PM
Ok I am now officially freaked out !  :shock:
Disturbing stuff.

If you're going to change something, change the monet list winner. Alter it from total money to "dollars per appearance". Call it a strike rate if you like.

Here you go ...

POTY = $$ * KK/(BLR*n)

POTY = points for player of the year award
$$ = total money won
KK = number of Krispy Kreme doughnuts you can eat in one sitting
BLR = number of bunker left & right at your home course
n = number of rounds you have played

I hope you find that equation less freakish ...  :wink:

This fomular won't work neither :(

My home course has no bunker.

You said things can't divide by "0"... if I can't eat any of those horrible donut, it will become
POTY = 49,000  * 0 /(0 *15)
hence:
POTY = 0 / 0
= Error....  :wink:

Jarro
13th May 2005, 02:41 PM
i like beer and porn 8)

3oneday
13th May 2005, 03:02 PM
he has his hands in the right order, unlike Jono :shock:
Thats the nicest thing you've ever said to me Pete. :lol:aww shucks :oops: :oops:

:P :lol: :lol: :P

Jarro
13th May 2005, 03:05 PM
he has his hands in the right order, unlike Jono :shock:
Thats the nicest thing you've ever said to me Pete. :lol:aww shucks  :oops:  :oops:

:P  :lol:  :lol:  :P

get a room you pair of pillow - biters :P :roll:

Trung
13th May 2005, 03:10 PM
Doc, you have lost the plot.. :?

Jono
13th May 2005, 05:56 PM
Doc, you have lost the plot..   :?

Plot? What plot ...? :lol:

Jarro
13th May 2005, 06:11 PM
nice work Doc 8)

i was going to submit my idea as well, but you seem to have covered everything rather nicely , so i'll save it :wink: :roll:

amanda
16th May 2005, 09:23 AM
Last year the voting panel (myself, Andyp and couple of others) as such looked at all the players and voted for Amanda based on a number of things, including effort.
Are you sure it wasn't because she is better looking than the other candidate?  :wink:
No - it was all based on my on-course exuberance! (ask the guys about the birdie at Horton Park or Jimandr about Glenmore :wink: )

AndyP
16th May 2005, 09:37 AM
No - it was all based on my on-course exuberance!  (ask the guys about the birdie at Horton Park or Jimandr about Glenmore :wink: )
Ahhh, yes, the birdie on the par 3 1st in pelting rain, I believe.  Very nice work.

markTHEblake
16th May 2005, 10:53 AM
No - it was all based on my on-course exuberance!  (ask the guys about the birdie at Horton Park or Jimandr about Glenmore :wink: )

ummm..... you already got the award by the time you played at HP, and we didnt see you at Glenmore Park.

in fact we had never met you at all = must have been your OFF course exuberance! :-)

Courty
16th May 2005, 04:48 PM
I think the formula should be whatever puts me on top of the list. I just checked my handicap history: 12 months ago I was on 11.5 (12) and today I am on 6.7 (7)... a 4.8 reduction in handicap. :shock:

I must say though, Blakey's argument has some merit in the fact that it is easier to drop shots when you are on a higher handicap and more difficult as you get lower. So that formula of Jono's (the part that I did read) needs some sort of allowance for that fact also... :roll:

Flowergirl
16th May 2005, 04:59 PM
Sorry......just read the above posts and the only one that makes any sense at all is "I like beer and porn".
:twisted:

Jarro
16th May 2005, 05:29 PM
Sorry......just read the above posts and the only one that makes any sense at all is "I like beer and porn".
:twisted:

i knew i'd strike a chord with you Reenie :wink: :lol:

Jono
16th May 2005, 05:44 PM
I think the formula should be whatever puts me on top of the list. I just checked my handicap history: 12 months ago I was on 11.5 (12) and today I am on 6.7 (7)... a 4.8 reduction in handicap.  :shock:

I must say though, Blakey's argument has some merit in the fact that it is easier to drop shots when you are on a higher handicap and more difficult as you get lower. So that formula of Jono's (the part that I did read) needs some sort of allowance for that fact also...  :roll:

Courty,

The formula I proposed DOES take into consideration the increasing difficulty as your handicap drops.  I called it the "difficulty multiplier", where your multiply your reduction in handicap by this number.  The difficulty multiplier increases as your handicap decreases (inversely proportional).

What I didn't take into consideration was that once you reach a handicap of 4, you suddenly lose only 0.1 per shot you shoot better than your handicap (whereas higher handicapers lose 0.2) and you also gain 0.2 per shot you shoot above your handicap. (whereas higher handicappers gain 0.1). So things suddenly get more difficult when you reach 4.

Anyway, if I have another sleepless night, I might plug in the figures into my formula and see how it compares with AndyP's ... Probably get called a wanker again, but then aren't all golfers ... never mind.  :wink:   :lol:

Courty
16th May 2005, 05:54 PM
The formula I proposed DOES take into consideration the increasing difficulty as your handicap drops.  I called it the "difficulty multiplier", where your multiply your reduction in handicap by this number.  The difficulty multiplier increases as your handicap decreases (inversely proportional).

My apologies, Jono. I must have given up before I got that far. :roll:

In that case, it sounds good (as long as I still end up on top :wink: )

Jono
17th May 2005, 06:49 AM
I punched in some figures into Excel using the formula I mentioned. However, instead of using plus 10 as the "best handicap", I used plus 5. Given that we don't play golf full time, I think it is safe to assume that none of us will ever get close to reaching the plus 5 handicap. I have seen amateurs go down to plus 3 though ...

Basically, by saying that plus 5 is the "best handicap", what we are saying it that the difficulty factor approaches infinity as you approach plus 5 handicap ... i.e. it is unattainable. This is not strictly true, but it does enable us to use the inverse proportional relationship between the handicap and the difficulty factor for handicaps above plus 5.

Anyway, here's the excel table. I've used the 24/4 handicap result from AndyP's thread. You can compare the old ranking under the percentage calculation and the new ranking with this calculation. As I said, it doesn't favour the lower markers as much.

http://members.optusnet.com.au/~ohjohn1/ozgolfimproved.xls

3oneday
17th May 2005, 07:05 AM
Day off today Jono ??? :P

:lol: :lol:

Jono
17th May 2005, 08:06 AM
Day off today Jono ??? :P

:lol:  :lol:

Yeah mate ... my last day off. 8 days in a row of 12 hour shifts from tomorrow ... :? I was hoping to get more golf in during my week off, but the weather hasn't been kind. It's raining today again. :cry:

Well, by the start of my next lot of days off, I should have my MP32's, ey? :wink:

Grunt
17th May 2005, 08:08 AM
When does the improvement date start?

as mine has my first handicap from having Mac Grange as my Home club. It was a fair bit higher @ Botany for some reason. Botany was not on golflink. I was on 27.5 on Nov 1st last year.

Is the improvent year 1st jan to 1st Jan?

Then I will not be as good as I had it lower than the 26.6 that is the start handicap for me. That would be 24.6.

It is as you can see my rating will change heaps depending on the dates

Grunt
17th May 2005, 08:12 AM
Ok I have used jono's formula to see what effect diferent dates have

if I take 1st nov to now I would jump up to 6th,

but if I take 1st Jan I plummet to 23rd.

Jono
17th May 2005, 08:33 AM
Ok I have used jono's formula to see what effect diferent dates have

if I take 1st nov to now I would jump up to 6th,

but if I take 1st Jan I plummet to 23rd.

I believe the improvement period started as of Nov 1st laster year and it will end at the time of Ozgolf champs this year.

So pat yourself on the back for being in top 10 ... :wink:

3oneday
17th May 2005, 08:37 AM
Well, by the start of my next lot of days off, I should have my MP32's, ey?  :wink:did you buy some ?? :shock: :shock:

Pete :lol: :lol:

Jono
17th May 2005, 08:47 AM
Despite being called a wanker (albeit implicitly) and accused of going whacko, I will persevere with my argument.

As I said earlier, AndyP's ranking system puts too much advantage towards the low markers.

Remember, this is the most IMPROVED player award ... not the most talented or hardest working ...

Say a 4 handicap plays once a week and practises twice a week just to keep his handicap. On the other hand, a 27 handicap plays once a fortnight and doesn't practise to keep his handicap at 27. So the 4 marker works harder just to stay where he is, but neither of them have improved.

The percentage system doesn't really give higher handicappers a chance. Consider that a 8 marker going down to 6 rates the same as 24 marker going down to 18. Yes, the 8 marker may have to work harder to get down to 6. But I believe the 24 marker going to down 18 has shown more IMPROVEMENT.

Courty
17th May 2005, 08:48 AM
Looks great, except you haven't updated my handicap to my NEW ALL-TIME LOWEST HANDICAP: 6.7  :twisted:

That would put me on top of the list...  :twisted:  :twisted:  :twisted:

Jono
17th May 2005, 08:49 AM
Well, by the start of my next lot of days off, I should have my MP32's, ey?  :wink:did you buy some ?? :shock:  :shock:

Pete :lol:  :lol:

Funny guy ... :roll: :wink:

Jono
17th May 2005, 08:55 AM
Looks great, except you haven't updated my handicap to my NEW ALL-TIME LOWEST HANDICAP: 6.7  :twisted:

That would put me on top of the list...  :twisted:  :twisted:  :twisted:

Courty, settle down ... :wink: Notice I haven't updated Trung's either.

I just wanted to show a comparison between AndyP's formula and mine. It shows that mid-high handicappers have a better ranking with my formula.

AndyP's table is still the "official" one ... :wink:

AndyP
17th May 2005, 09:52 AM
Start a poll. ;)

I’m not fussed, I was just taking the simple way, that required little thought.

Courty, either way you will be at number 2. Jono was just using the 24/4 figures for comparison.

Courty
17th May 2005, 11:10 AM
Start a poll.  ;)

I’m not fussed, I was just taking the simple way, that required little thought.

Courty, either way you will be at number 2.  Jono was just using the 24/4 figures for comparison.

:oops: :cry: :oops: :cry: :wink:

AndyP
17th May 2005, 11:15 AM
Courty, either way you will be at number 2.  Jono was just using the 24/4 figures for comparison.

:oops:  :cry:  :oops:  :cry:   :wink:
And we all know that 2nd is just the first placed loser.   :P

Jono
17th May 2005, 11:19 AM
:oops:  :cry:  :oops:  :cry:   :wink:
And we all know that 2nd is just the first placed loser.   :P

You mean Trung is the WINNER?  That can't be right ...  :?

Hang on ... let me tweak the formula a bit ...  :twisted:

Trung
17th May 2005, 12:14 PM
You mean Trung is the WINNER?  That can't be right ...  :?

Not WINNER :shock:

I'm the current LEADER :smt006 :smt030 :smt026 8-[ :mrgreen: \:D/

3oneday
17th May 2005, 12:29 PM
And we all know that 2nd is just the first placed loser.   :Psooo, if Courty is the first placed loser, what sort of loser is Trung :?

:lol: :lol:

Courty
17th May 2005, 01:42 PM
Courty, either way you will be at number 2.  Jono was just using the 24/4 figures for comparison.

:oops:  :cry:  :oops:  :cry:   :wink:
And we all know that 2nd is just the first placed loser.   :P

=; Talk to the hand, Andy. :wink:

Trung
17th May 2005, 02:15 PM
And we all know that 2nd is just the first placed loser.   :Psooo, if Courty is the first placed loser, what sort of loser is Trung  :?

:lol:  :lol:

:smt047