Which AJGA?

[mrshinsa]

If given exemption, which OPEN would you play and why?

Edited August 11, 2023 by mrshinsa

[leezer99]

I'd find the course that best suits your junior golfer's game. In my case that would be one with no trees, 98 yard wide fairways and slow flat greens. 🤣

[kcap]

the tournaments that involve the least amount of travel.  I am tired of paying for hotel rooms..



 

[wegobomber31]

On 8/10/2023 at 10:59 PM, mrshinsa said:

If given exemption, which OPEN would you play and why?

Really depends what you’re going for, but I’d probably just pick ones close to you. 
 

One thing I’ve noticed is some of the ones with minimum points above 40 don’t really have the strength of field to warrant it. 

[iteachgolf]

On 8/11/2023 at 2:35 PM, Jcracks said:

To the poster that is confused.  JGS rankings implement a course rating adjustment.  The adjustment is an algorithm based on the quality of the field.  The better the field the better the CCA which allows players to rank higher.  If a course rating is a 75 and the field is strong the CCA could be as high as a 75.  Meaning your 75 against that field is better than a 75 in a tournament where the rating is a 72.

Not exactly how it works

[iteachgolf]

4 minutes ago, Jcracks said:

It is exactly how it works.

No it’s not.  It’s average scoring differential of that round vs average scoring differential in field in prior events.   If rating is 75 the CCA could bump it to 78.  Plenty of weak fields get bumped to the max and plenty of strong fields don’t get adjusted at all or even down.  It’s not based on quality of field (though bigger fields have better odds of being adjusted up).  I have a spreadsheet with formula and can see what CCA will be before it’s posted.  I can also see what differentials would be without any CCA adjustment 

[kcap]

I do not have a spreadsheet.  But I do have the link to JGS explaining the CCA.   The methodology is pretty simple and crystal clear.   It looks at scoring differential vs prior round and makes adjustment.   Knowing how to use the CCA to your advantage is a separate topic. 

https://www.juniorgolfscoreboard.com/cca.asp

 

To explain, our system:

• For fields of 10 or more ranked players, statistically looks at the historical playing ability of the middle of the field (not the best players or the weakest). It does that by statistically analyzing their scoring differentials from the rankings date closest to the start of the tournament.
• Compares that analysis to the same group's differential for each round
• For split field events where the field is split each day on different courses, the Course Condition Adjustment is computed for that course in that round using the players who played the course that round.
• Determines if the difference between those two averages is statistically significant and either decreases or increases the course rating accordingly.
• Has a maximum rating increase adjustment of 4 shots, decrease adjustment of 2 shots and adjusts ratings by whole shots only.

As always, as more data becomes available, we will evaluate refinements and adjustments as they become apparent.

[iteachgolf]

29 minutes ago, Jcracks said:

I have a spreadsheet as well.  It is a strength of field rating based on the scoring differential after dropping the top 10% and bottom 10% of the field.  The stronger the middle portion of the field, the stronger the CCA.  Therefore, it is a strength of field adjustment with better fields getting better adjustments.  AKA the AJGA Bump.  

It’s not a strength of field rating at all.  If a really strong field shoots lower scores then their average differential CCA will adjust the rating DOWN.  Just like if a bad field has higher than average differentials it gets adjusted up.  It’s based on expected score vs actual score, doesn’t matter the strength of the field.   It’s why plenty of REALLY strong fields receive zero CCA adjustment.   It’s purely based on expected outcome vs actual outcome, if a course plays easier than expected (like the harder of the two courses day one at the US Jr) CCA won’t be bumped up no matter how strong the field is. 

[TroyB123]

13 minutes ago, iteachgolf said:

It’s not a strength of field rating at all.  If a really strong field shoots lower scores then their average differential CCA will adjust the rating DOWN.  Just like if a bad field has higher than average differentials it gets adjusted up.  It’s based on expected score vs actual score, doesn’t matter the strength of the field.   It’s why plenty of REALLY strong fields receive zero CCA adjustment.   It’s purely based on expected outcome vs actual outcome, if a course plays easier than expected (like the harder of the two courses day one at the US Jr) CCA won’t be bumped up no matter how strong the field is. 

Yeah, that's a good explanation.   It seems large field events where everyone has a JGS ranking get ranked fairly one way or another no matter what the actual strength of field is or whether it is ajga or not.  

 

It can get a little unfair when there are a smaller number of ranked players in a field and not enough data to make the appropriate adjustment.

 

I suppose if you could somehow find an AJGA event where you know they have a lot of over-ranked players (ie players with low differentials playing lesser events with questionable oversight or exagerated course rankings), then that would be a good one to pick.   Good luck with that endeavor though!

[TroyB123]

13 minutes ago, Jcracks said:

You are wrong.  It is a strength of field adjustment based on "what that field should shoot based on the differentials of the middle portion of the field.".  That is a strength of field adjustment.  The better the field, the better the adjustment.  Look at every AJGA Invitational,  USGA Jr, Sage Valley, Dustin Johnson, PGA Jr and they all have close to maximum adjustments.  When looking at AJGA Bigger Opens the same adjustments are given because of strength of field.  

 

Really strong fields receive zero CCA adjustment only when scoring expectation are met and that does not happen very often.  Can weather effect it, yes, but it is still based off of scoring by the strength of field.

 

 

You keep telling everyone they are wrong, but you are not really following the math and logic.   A lot of the tournements you mentioned have very tough set ups.  If a kid is confident they can thrive on a very tough course and set up and beat a lot of good players, then yeah those can be good opportunities.   But just having a strong field doesn't make it a large CCA.

 

I randomly looked up a couple of AJGA invitationals.

https://www.juniorgolfscoreboard.com/smtresultscourse.asp?tid=63611

 

CCA was 1,2,0 for the 3 days.   Same field every time with no cut.

 

https://www.juniorgolfscoreboard.com/smtresultscourse.asp?tid=64276

 

CCA was 0,0,1   

 

 

 

 

[iteachgolf]

1 hour ago, Jcracks said:

You are wrong.  It is a strength of field adjustment based on "what that field should shoot based on the differentials of the middle portion of the field.".  That is a strength of field adjustment.  The better the field, the better the adjustment.  Look at every AJGA Invitational,  USGA Jr, Sage Valley, Dustin Johnson, PGA Jr and they all have close to maximum adjustments.  When looking at AJGA Bigger Opens the same adjustments are given because of strength of field.  

 

Really strong fields receive zero CCA adjustment only when scoring expectation are met and that does not happen very often.  Can weather effect it, yes, but it is still based off of scoring by the strength of field.

 

Nah. You’re wrong.  It’s a way to equalize scores when courses play significantly harder/easier than their rating.  Can be because of weather, course setup, actual yardage vs stated yardages.   Again it’s not strength of field.  The US Jr didn’t get the full adjustment at all, Day 1 didn’t get adjusted at all on tougher course.   Those events are adjusted because they are setup significantly more difficult than when the course is rated (slower greens, shorter rough, easier hole locations).  The bigger the event the more different the course is setup from how it plays in every day play.  Winter FJTs with weak fields in North FL where it’s cold and windy get max adjustment, and they have weak fields because most top players won’t play in them because they don’t want to have high scores in their rankings.  I’ve seen several local level events get max adjustment with very weak fields. 
 

Again it’s just numbers and it’s simply expected vs actual.  Field size has more to do with it than field strength (number of ranked players).  

[iteachgolf]

Hard courses get adjusted up. Regardless of field.  A Hurricane event at Mission Inn got adjusted up 4 shots. An FJT at Mission Inn got adjusted up 4 shots.  

[TroyB123]

18 minutes ago, iteachgolf said:

Hard courses get adjusted up. Regardless of field.  A Hurricane event at Mission Inn got adjusted up 4 shots. An FJT at Mission Inn got adjusted up 4 shots.  

With the caveat that there has to be enough ranked players in the field to get a meaningful (or any) adjustment.   AJGA you can count on that happening.  Hurricane is hit or miss.   

[wegobomber31]

I looked at the tournaments in the golfweek rankings dataset that had roughly similar field size (44 to 56 players).  There were 98 such events over the last year, so I could break that into deciles by strength of schedule and see what the JGS CCA was per round of the tournament.

 

[wegobomber31]

6 minutes ago, Jcracks said:

The way I am reading the table is the better the strength of the field the more likely that field was going to get a helpful CCA?

I just posted the data without commentary.  Read into it what you will.

[wegobomber31]

1 hour ago, Jcracks said:

AJGA Opens are not tough set ups.  The adjustments are all based on strength of field with an algorithm designed for a hypothetical of what that field should shoot.  If that field shoots the target score that compares against the score from similar strength of fields then there is no CCA.    @wegobomber31 just proved me correct that there is an AJGA bump.  It is not intended, but it is there.

 

I don't really think there is a AJGA bump, as close to 40% of the events didn't receive any adjustment or had a negative one.  If you sort just the AJGA events by strength of field, the highest SOS events definitely have a higher adjustment, on average.

 

Name	Strength (rank)	# in Group	# of Groups	CCA	Rounds
2023 AJGA Sergio & Angela Garcia Foundation Junior Championsh	72.64(17)	1	49	10	3
2023 AJGA Junior At Canebrake April 21-23	72.93(19)	1	47	0	3
2023 AJGA Will Lowery Junior Championship April 14-16	73.46(26)	1	45	7	3
2023 AJGA Justin Thomas Junior Championship April 21-23	73.57(27)	1	51	10	3
2022 AJGA Accenture NW Arkansas Junior September 3-5	73.76(29)	1	56	9	3
2023 AJGA Mizuno/Keith Mitchell Junior Championship July 10-1	73.82(31)	1	50	11	3
2023 AJGA Under Armour/Jordan Spieth Championship June 27-29	73.91(32)	1	51	0	3
2023 AJGA UNIQLO / Adam Scott Junior Championship May 26-28	73.92(33)	1	49	0	3
2023 AJGA K.J. Choi Foundation Texas Junior Championship Marc	73.93(35)	1	44	1	2

 

 

AJGA Group	Count	Golfweek SOS	JGS CCA/Round	% w/ <=0 Adj
Group 1	9	73.44	2.24	28.6%
Group 2	9	74.13	0.60	28.6%
Group 3	9	74.71	1.05	14.3%
Group 4	9	75.02	1.14	42.9%
Group 5	7	75.47	0.90	42.9%

 

 

[iteachgolf]

1 hour ago, Jcracks said:

AJGA Opens are not tough set ups.  The adjustments are all based on strength of field with an algorithm designed for a hypothetical of what that field should shoot.  If that field shoots the target score that compares against the score from similar strength of fields then there is no CCA.    @wegobomber31 just proved me correct that there is an AJGA bump.  It is not intended, but it is there.

TLGT got a way bigger bump than AJGA opens.  And TLGT and Hurricane events were actually more likely to get a CCA bump than AJGA Opens (HJGT got a smaller bump but more often).  

[TroyB123]

Hurricane events often have half the field not ranked in JGS and is probably why they get smaller bumps.

 

The strongest field events are also more likely to be on tougher courses/setups.

[wegobomber31]

There is an inherent flaw (flaw might not be the right word for it, but it's a weird nuance) in the CCA methodology.  CCA is based on what a '0' Diff would be expected to shoot on this day, and they take the middle 80% of the field and their expected score relative to the ranking.  But the Diff is based on the best 75% of scores.  Really they should remove the worst 25% of performances relative to expectations and then compare the field's scores relative to that for assessing whether a CCA is warranted.  In other words, the DIff reflects the best 75% of scores whereas the CCA is assuming this is their typical performance.

 

As a result, you get a downward drift over time.  I don't think a -8 Diff is really 8 strokes better than a 0 Diff, but the CCA approach assumes that is the case. So when a -8 Diff shoots a 74, the CCA assumes it's because of tough conditions whereas it might just be one of those 25% bad rounds that aren't in his Diff in the first place.

 

[TroyB123]

5 minutes ago, wegobomber31 said:

There is an inherent flaw (flaw might not be the right word for it, but it's a weird nuance) in the CCA methodology.  CCA is based on what a '0' Diff would be expected to shoot on this day, and they take the middle 80% of the field and their expected score relative to the ranking.  But the Diff is based on the best 75% of scores.  Really they should remove the worst 25% of performances relative to expectations and then compare the field's scores relative to that for assessing whether a CCA is warranted.  In other words, the DIff reflects the best 75% of scores whereas the CCA is assuming this is their typical performance.

 

As a result, you get a downward drift over time.  I don't think a -8 Diff is really 8 strokes better than a 0 Diff, but the CCA approach assumes that is the case. So when a -8 Diff shoots a 74, the CCA assumes it's because of tough conditions whereas it might just be one of those 25% bad rounds that aren't in his Diff in the first place.

 

That's a good point.  They should really use all the scores available per player.  I also find the middle 80% a weird methodology.  It would make more sense to throw out the 10% who were most over their differential and 10% most under their differential and write those off as outliers.   

[wegobomber31]

2 minutes ago, TroyB123 said:

That's a good point.  They should really use all the scores available per player.  I also find the middle 80% a weird methodology.  It would make more sense to throw out the 10% who were most over their differential and 10% most under their differential and write those off as outliers.   

Yeah even if they don't publish it they could calculate the avg diff from using 100% of the scores and then use that in the CCA.  It would have to reduce the number of tournaments that got an adjustment.

[golferdad8]

10 hours ago, Jcracks said:

AJGA Opens are not tough set ups.  The adjustments are all based on strength of field with an algorithm designed for a hypothetical of what that field should shoot.  If that field shoots the target score that compares against the score from similar strength of fields then there is no CCA.    @wegobomber31 just proved me correct that there is an AJGA bump.  It is not intended, but it is there.

 AJGA Opens can be easier or more difficult - so it's wrong to say that over 100 AJGA opens are not tough set ups. 

 

The most important flaw with JGS and CCA is "garbage in - garbage out" on the current players. 

 

Similar to some colleges being easier than others, look at the top players. 

FL, TX, SoCal, etc...appear to have inflated scoring differentials due to higher rated/longer courses, esp vs. NorCal. 

Also, check out int'l players w high scoring differentials with only 4 or 5 tournaments where they cherry pick.

 

How do I know these #s are wrong? check out what happens when these "top ranked players" compete in national tournaments and don't perform as well as their JGS ranks/scores should be. Just my 2 cents. 

[kcap]

On 8/14/2023 at 1:21 PM, kcap said:

Compares that analysis to the same group's differential for each round

 

16 hours ago, wegobomber31 said:

There is an inherent flaw (flaw might not be the right word for it, but it's a weird nuance) in the CCA methodology.  CCA is based on what a '0' Diff would be expected to shoot on this day, and they take the middle 80% of the field and their expected score relative to the ranking.  But the Diff is based on the best 75% of scores.  Really they should remove the worst 25% of performances relative to expectations and then compare the field's scores relative to that for assessing whether a CCA is warranted.  In other words, the DIff reflects the best 75% of scores whereas the CCA is assuming this is their typical performance.

 

As a result, you get a downward drift over time.  I don't think a -8 Diff is really 8 strokes better than a 0 Diff, but the CCA approach assumes that is the case. So when a -8 Diff shoots a 74, the CCA assumes it's because of tough conditions whereas it might just be one of those 25% bad rounds that aren't in his Diff in the first place.

 

 

The methodology mentioned on JGS website states that it looks at the difference for " each round" not the best 75%.

 

That should clarify your concerns about downward drift.

 

 

 

[wegobomber31]

18 hours ago, kcap said:

 

 

The methodology mentioned on JGS website states that it looks at the difference for " each round" not the best 75%.

 

That should clarify your concerns about downward drift.

 

 

 

i realize they are using each round. This is what is causing the downward drift. They are comparing “average” scores against Diff’s that are based on “good” rounds and chalking up the difference to course conditions, set up, etc. That leads to more CCA’s, which leads to lower Diff’s and the cycle continues. 

50th ranked player:

2 years ago: -4.33

1 year ago: -4.98

Today: -5.30

100th ranked player

2 years ago: -3.60

1 year ago: -4.02

Today: -4.30

 

200th ranked player

2 years ago: -2.51

1 year ago: -2.90

Today: -3.08

[RobS]

To the original question, I'd factor in which event is closest to home with which course favors your kids playing ability/strengths.