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iacas

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Blog Comments posted by iacas


  1. 7 hours ago, Jeremie Boop said:

    I always struggle with wanting to hit good shots when trying to fix aspects of my swing. I'm very bad at wanting/expecting instant results when I work on drills.

    It's always been very difficult for me to stick with something that doesn't seem to be working because I'm not hitting good shots, but after all this time it's become readily apparent to me that when I try to use things "that work" for me on the range rarely work for long and tend to end up causing me more problems down the road.

    Read that Jeremie.


  2. 22 minutes ago, Lihu said:

    You erased what Erik wrote for me to get something together? So, what specifically are you stating I need to get together a thousand times over?

    He didn't erase anything. Single digits = < 10.

    What does a 155 sloped course have to do with anything?

    You also said:

    On April 10, 2016 at 3:46 PM, Lihu said:

    What I consider a true single digit player is someone with a sub 7 index, and can tackle a random 155 course with a score below 80 once in a few rounds.

    1. An 8 is a single digit handicapper. So is a 9. By definition.
    2. A 155 rated course is a 2.1 index differential. That means a 2.1 index golfer will only break 80 on that type of course about 20% of the time. Your math is way, way off.

  3. 3 hours ago, nevets88 said:

    There's just your head coming "off the wall", just your derriere, and both head and derriere. Are the three about the same? 

    No. The head alone would generally be the "better" of the set.

    2 hours ago, billchao said:

    A well-timed entry for me. I started wondering about this in my own swing.

    Though TBH I already knew the answer, but this helps reinforce it and keep me from working on something stupid and unnecessary.

    Yeah. A lot of golfers have a little of this.

    2 hours ago, bm85 said:

    It was one of those things that was cloudy for me, because 1.) Seems like I hit the ball great lately, and 2.) my goat was a little bit humped.

    Only solution was to exaggerate sucking my left hip back on the down swing (often pulling my head with it), or changing my back swing entirely which I didn't like the idea of, having worked on it now for a solid year (I prefer modifying at this point, not going full tabula rasa). 

    Glad it could help!


  4. Quote

    I want to thank you all for reading this... and for the friendly atmosphere of the site.

    Thank you.

    The site would not be what it was without good folks like you.

    I know in this day and age we can talk about how the Internet is keeping people isolated and alone, but right now while my wife is asleep, I get to read a nice story by a guy I've never met and which makes me feel like I'm a bit closer to you asa  human, when otherwise I'd be reading and/or watching TV.

    So again, thank you, Shane.


  5. 16 minutes ago, newtogolf said:

    I know a lot of people that belong to clubs that complain about the sandbaggers in their club.  Could be sour grapes but the perception is they are sandbagging. 

    I agree vanity capping is more common but that works against the vanity cappers that play for money or in tournaments so people don't get as outraged about it.  

    Right… so maybe the vanity handicappers are just pissed that others with legit handicaps are not vanity capping like they are, so they write it off and complain about them as "sandbaggers."


  6. 40 minutes ago, natureboy said:

    The degrees offline are applied along the distance of the player's average shot distance. Percent comparison accurately shows that for the skill of holding their target line, a bogey golfer 's ability is worse in relative terms than with distance where a scratch player at 250 yards only hits it 25% farther than bogey at 200 yards. They work hand in hand so relative % difference in skill in both distance and degrees offline is descriptive of the difference in relative skill between bogey golfers and scratch golfers.

    I continue to disagree. You can't compare the differences in small numbers like degrees versus the the difference in large numbers like yards, when both are done as a percentage.

    40 minutes ago, natureboy said:

    Here's the same relationship converted to strokes value (per Broadie's #'s) of different skill levels vs. scratch…

    I'm aware of what the data shows.

    The point that you seem to be missing is that you haven't proven or even really begun to demonstrate knowledge of how the rating/slope accounts for this now or begun to make a case as to why it should be changed.

    40 minutes ago, natureboy said:

    Yet the assumptions in the rating guide hold an expectation of bogey golfers as having the same Std Deviation of Degrees Offline as scratch golfers.

    They do not. Not really. I've already addressed this a few times. I realize with your condition that you're going to keep hammering away saying the same thing over and over, but I'm about tapped out (again).

    40 minutes ago, natureboy said:

    56edf31f4abdb_sloperatingdispersiontable

    The expected landing area for a scratch golfer at 200 yards is 29 x 19, and 33 x 37 for the bogey golfer at 200 yards. At 100 yards, it's 11 x 14 and 16 x 20. And that's 2/3 of the time.

    40 minutes ago, natureboy said:

    I'm not saying it will or should lower all Bogey HCPs, The difference in average score for bogey relative to scratch is what it is.

    No, it isn't "what it is" because your changes would change "what it is."

    40 minutes ago, natureboy said:

    A more accurate formula would just do a better job of making the bogey rating and slope more accurate for the particular course.

    You keep saying these words as if you've demonstrated or proven something, but you haven't even begun to do that.

    40 minutes ago, natureboy said:

    It would eliminate a potential area for intentional or unintentional 'sandbagging' from playing very tight / treed courses where the relatively higher dispersion for a bogey golfer is not well accounted for by the rating system. I don't think it's going to award 'extra' HCP points, just reflect a player's average score on different courses more accurately and increase the portability, which was the original purpose of slope.

    I think you're wrong on what it would do, and that you've not demonstrated sufficient knowledge of what the system accomplishes, how it's truly set up now, and how the changes you keep pushing would actually change things.

    Again, there are probably not even these massive stands of trees on enough holes (on both sides) that this would have much of an effect at all. Oh, and they have to be far enough away to be outside the landing area, but not so far away that they're not ridiculously far away.

    That's not even a thing you're likely to find very many places at all, I'd imagine.

    I'm done now. Please leave me out of it from here. I'll pass this along to my ratings guy and if he has anything more to add, I'll post a summary.


  7. 4 hours ago, natureboy said:

    Percentage change is actually ideal in comparing the relative difference in distance (yards) and accuracy (degrees offline from target) between the different skill levels that bogey rating / slope is attempting to capture. Even if you convert the degrees offline to a lateral dispersion in yards at the shorter distance the higher HCP's hit the percentage difference / change from Scratch golfers is larger (more sloped) than for drive distance.

    I disagree that it's an ideal way of comparing things. One compares small numbers (like 3° and 10°) while another compares significantly larger numbers (250 and 220 or whatever).

    4 hours ago, natureboy said:

    I know, because distance accounts for ~ 90% of the formula, which is likely too heavy a weight.

    You haven't demonstrated at all that it's "likely." That's just a manner of rephrasing your opinion.

    4 hours ago, natureboy said:

    Bogey golfers do not have the average dispersion of scratch golfers.

    Nobody is debating that. It's a given.

    4 hours ago, natureboy said:

    Therefore attempting to evaluate the higher relative difficulty they face on a certain course should take this fact into account more in line with its statistical impact on score.

    You haven't argued your case at all. Trees are accounted for more for higher handicappers, in a few ways. That you think they should matter even more is what you have to argue, and except for saying things like "they should matter more" (while not demonstrating much specific knowledge about how much they currently change things), you have not done so.

    3 hours ago, natureboy said:

    I read this already. This is where I learned how little trees affect bogey rating / slope.

    That paper demonstrates how little the course rating is affected by trees. If you want to argue that they should matter more, you first have to demonstrate knowledge about how much they matter now and why that's not sufficient.

    3 hours ago, natureboy said:

    Their 'simulation' is a tautology comparing the output of the same formula with different inputs. It's just an example / demonstration of how little weight trees have in the existing formula.

    And, you have to demonstrate both knowledge of that current formula and demonstrate why it's inefficient. Trees are already given more weight for the bogey golfer.

    3 hours ago, natureboy said:

    It's not as Broadie does running a dynamic programming simulation between different course setups with a statistical model of a scratch and bogey golfer to see the expected impact on average score.

    This is where you also start to get into circular nature of what you're proposing… Let's suppose the USGA decides to indulge you. So now an 18 (course) handicapper plays a course rated 72.4/150 instead of 72.4/125. He shoots the same score (about 90 or 91 in his 10 of 20 that count) because, you know, nothing about the course has changed at all. So his 90s in the 10 of 20 rounds that count result in an index has dropped from 15-point-something to 12-point-something.

    In other words, the fact that the guy is an 18 is part of what leads to his higher scoring and thus his higher handicap. By increasing the difficulty, the worse the golfer you are, the bigger the benefit you get in reducing your handicap.

    Heck, a 36 handicapper would, overnight, be a 29.x-handicapper? Despite shooting the same scores… because you've inflated the course index?

    So then that now-30 handicapper goes and plays a scratch golfer on a course without many trees and… gets creamed.

    That's the problem, and one of the several things for which you don't seem to be accounting.

    3 hours ago, natureboy said:

    Even if an estimate of 3 extra (likely low) tee shots to the trees for a bogey golfer is correct that's 3 potential stroke & distance penalties (6 strokes) because even if the trees are rated as fairly 'recoverable' the chances of a lost ball are going to be quite high.

    No way is 3 strokes "likely low."

    I've played with bogey golfers on courses rated in the 140s with lots of trees and stuff, and no way do they take three stroke-and-distance penalties per round. That would require two things which are highly unlikely to all happen: 1) player has to find the woods three times, and 2) lie has to be so bad player has to take three unplayable lies with stroke and distance.

    Then that round also has to count for their handicap, despite six penalty strokes (effectively)?

    Guess what actually happens?

    a) "unrecoverable trees" do not exist on both sides of fairways very often. When they do, the course rating and slope is already a bit higher.
    b) the player aims away from the trees.
    c) the player doesn't hit a driver.

    etc.

    Your entire argument is, IMO, a non-starter. You'd actually be punishing the higher handicappers, and the more you increased the rating, the more you'd be punishing them. Why do you want a 20-handicapper to call himself a 16?

    At the end of the day, courses with a lot of super-thick stands of trees are already rated higher. Bogey golfers already get more benefit from their lack of accuracy than scratch golfers (namely that we must consider the maximum tree value along the entire corridor, not just within the landing area).

    That those things already don't drastically change the course rating demonstrates the USGA's position on how much trees should affect things.


  8. To the point I was making above…

    Quote

    A CASE STUDY

    To illustrate how trees may impact the Course Rating and Slope Rating, a simulation from a golf course with minimal trees is provided. The actual Course Rating and Slope Rating are 73.8 and 128, respectively. When a moderate obstacle value for trees is added to all 18 holes, the Course Rating and Slope Rating rise to 74.4 and 139, respectively. When a high obstacle value for trees is added for all 18 holes, the Course Rating and Slope Rating rise to 75.0 and 147, respectively.

    The Course Rating and Slope Rating increase as the obstacle value for trees increases, but this simulation accounts for more trees across all 18 holes on the course. In the event that a few trees are removed or added to a single hole, it is highly unlikely that the Course Rating or Slope Rating will change at all. This is particularly true when trees are 30 or more yards from the centerline of the hole. 

    http://textlab.io/doc/1087995/how-trees-impact-usga-course-rating™-and-slope-rating®


  9. I'm still mostly done talking about this, because you've yet to convince me of anything at all, but surely you can see the folly in normalizing to a percentage when one set of numbers is almost 60x the other (250 yards versus 4° or whatever).

    Plus, again, trees are already considered. Guess what? This might drive you nuts, but trees rated as a 6 on every hole versus trees rated as a 2 on every hole of the golf course… barely changes the course rating or slope.

    So… if the guys in charge of building course ratings barely give much weight to ALL the trees on the entire course WITHIN your 30 yard boundary… what makes you think they're ever going to care about trees 35 yards away?


  10. Just now, natureboy said:

    So why have slope at all?

    Because the benefits were worth the cost.

    Just now, natureboy said:

    Slope is primarily distance based to reflect the relative difficulty of courses with many obstacles requiring greater skill in "ability to overcome distance".

    The entire course rating system is primarily distance based. The other obstacles on the course are weighted differently for scratch and bogey golfers.

    Just now, natureboy said:

    Accuracy is another fundamental skill that's on the same kind of slope from low HCP to high HCP as distance. "Better players are longer and straighter".

    Accuracy is already considered in the slope rating. Green size targets, fairway widths, the entire corridor (mounds, trees, etc.) are considered instead of just those within close proximity of the landing area… etc.

    Just now, natureboy said:

    I expect that distance weighted 90% is an inherent assumption that may merit revisiting at the same time they get around to updating the average distances from the 1975 values.

    You seem to be operating under a number of false assumptions.

    As I've said several times now, those trees are weighted and considered. Just not very much.

    I currently find little wrong with the course ratings, and have exhausted my interest in this topic and find that you've not yet persuaded me of anything.


  11. 28 minutes ago, natureboy said:

    If 30 yards from the center line is the +/-1.33 sigma or 80th percentile for scratch players then evaluate the hole at the same 80th percentile for bogey golfers, which will be a larger distance from the center line.

    Why? Because it appeals to what you feel is fair? There's nothing inherently "fair" in scaling up the difficulty of things when golfers suck more. That's already accounted for in their higher scores. Guess what? Sucky golfers are more likely to find water hazards, too. Or bunkers. Or hit it OB. And if 90% of a course's rating and slope come from distance… any change you make to this will be incredibly small anyway. Again, does it really matter if a slope is 139.999 or 140.002?

    28 minutes ago, natureboy said:

    Or keep the same distance from center line for bogey golfers and evaluate scratch golfers at the same equivalent percentile distance of their standard normal shot dispersion (which will be smaller / tighter).

    Why? They don't make bowling alleys wider for players who suck at bowling. The game is what it is.

    28 minutes ago, natureboy said:

    It assumes an average distance for the scratch and bogey golfer even though there is the same individual variance within these HCP groups as with shot dispersion.

    No, it doesn't.

    Furthermore, you can find any number of players who are more accurate in part because they're shorter. And again, they don't widen the bowling alleys… If you suck and hit the ball into the trees more than you should, your score will reflect the higher handicap that you are.

    28 minutes ago, natureboy said:

    Well then there are few / no trees in that expected landing zone.

    No. 40 yards away is not the landing zone.

    28 minutes ago, natureboy said:

    Where I'm thinking the current system most under-accounts for trees is courses with dense deep stands (woods) of trees extending from ~30 to 65 yards from center line, not your 'typical course' with a line of trees between holes.

    And I think you're wrong.

    A golfer who hits the ball regularly offline that far and finds the trees deserves to shoot the higher score and have the higher handicap.

    In other words, you have two identical golfers except for one thing: one hits the ball within about 30 yards of the center of the fairway, the other does not. Why shouldn't the gap between the two golfers represent that difference? Let's say it's three shots per round. Why should the wilder golfer be given an advantage that reduces it to only 1.9 shots per round?

    Also, you seem to be continuing to ignore the fact that we already consider hazards (trees, mounds, etc.) along the entire playing corridor of the bogey golfer, while only considering those within about 20 yards for the scratch golfer. This is because the bogey golfer might shank one off the tee while a tree 100 yards off the tee does not ever really come into play for the scratch golfer. So they're already getting an "advantage" on the tree rating.


  12. 3 minutes ago, natureboy said:

    Because then you would be comparing the same standard deviation of degrees offline between the scratch and the bogey golfer...you would be comparing the same degree or percentile of 'bad shot' relative to the standard normal distribution of shots for each golfer. Apples to apples.

    That's not apples to apples. Ultimately, players will shoot some number over the course rating and that number is affected somewhat by the slope. But poorer players are poorer players, and you're saying they deserve to have their ineptitude softened. I disagree.

    Besides… guess what? On some courses missing the center line of the fairway by 40 yards is an advantage because it puts you in another fairway corridor. So how do you account for that, now? That's rhetorical, btw.

    3 minutes ago, natureboy said:

    Why have a handicap or slope system at all? The course is the course, the score is the score, right?

    You're the one arguing for change. I'm the one saying it's pretty good right now. Don't put words in my mouth.

    3 minutes ago, natureboy said:

    Why look at course / hole distance when factoring slope? If you can't hit it as far as a scratch player, tough. You're just a bad golfer - go hide your head in shame, bad golfer, bad! :-P

    That's not at all what I've said.

    Trees > 30 yards away are taken into account, just minimally. At some point you have to stop considering what may or may not be in play on a hole, or their weighting factor becomes essentially nil anyway. Do you really care if a course's slope is 139.999 or 140.002?

    3 minutes ago, natureboy said:

    More skilled players have a distribution of drive distances that is on farther on average than higher handicaps. Slope specifically & explicitly accounts for that. A scratch golfer's shot distribution is also tighter than a bogey golfer's. If slope is meant to 'look at the course from the eyes of a bogey golfer', then the relative difference in shot dispersion should be part of it too.

    It already is.

    3 minutes ago, natureboy said:

    Besides, IMO re-tweaking the formula isn't going to really change HCP's relative to a scratch golfer just more accurately reflect a 'portable' HCP if one course is actually more difficult for the 'typical' bogey golfer than another.

    Not sure what you meant to say there.

    Courses have a rating and a slope. The slope adjusts for a handicap for a "bogey golfer." It does so linearly, because to calculate so otherwise would take up far too much time and be too tedious.

    As mentioned above, it's a pretty good system that does what is ultimately impossible: provide a universal handicap system that can be applied to courses thousands of miles apart and to players of vary different abilities.

    Some 72.5/133 courses will play easier to player A than another 72.5/133 course, while some will play more difficult to player B.

    3 minutes ago, natureboy said:

    The point of referencing Dean's proposal article was that there was at least one built in assumption shown incorrect by subsequent data collection. It's very common with models. I think what Dean Knuth did is awesome. Do you think the model is perfect and could not possibly be revisited for accuracy?

    Again, I'll ask you not to put words in my mouth. I have not said the model is perfect, but I don't even know that you know what the model is. It's up to you to prove that something needs to be changed, and you don't even seem to know what the current calculations are.


  13. 3 hours ago, natureboy said:

    I just observed that the rating guide had a somewhat arbitrary distance cutoff when it's clear from Mark Broadie's statistics that as HCP's rise for typical golfers average distance drops and shot dispersion increases. Margins of error are different for the different types of golfers and that affects scoring. If there was a sliding scale that had a distance from centerline that returned the same appx z-score (same standard deviation value) as for scratch golfers, I would consider that more fair. It may be that looking at trees along the whole hole helps bogey golfers, but I'd put my bet on a higher fraction of tee shots to the woods mattering more.

    Why is that more fair?

    They're worse golfers. Why should the scale keep sliding up and reducing their handicaps?

    Also, you seem to be unaware of the fact that the weights of things and these values and so on keep changing, nearly yearly. The many factors are weighted differently all the time, subtle changes are made constantly.

    The system cannot and is never intended to adapt to all golfers. There are long-hitting wild 14 handicappers and short but straight and accurate 14 handicappers. No system will truly rate all golf courses appropriately for all golfers. The system we have now is pretty darn good, and I don't think we need to care about something 35 yards from the center of the fairway when we already do weight it, just not very much. If you hit it 40 yards offline, well, you suck, and you shouldn't get a an advantage by having the slope be 144 instead of 141. And, really, what's that few points going to do anyway? Very little.

    1 hour ago, natureboy said:

    Here's an example in the rating factors that goes against Broadie's data which show that being in the rough matters less to higher HCP's than more skilled players. Just saying it might be time for an update / tweak to a generally very good system.

    The system is updated all the time @natureboy.

    You don't even know how old that article is, or what the current values are.


  14. 1 minute ago, natureboy said:

    I don't think you're saying slope should not be part of the HCP calculation?

    Not saying that at all. Not sure how you'd get that from what I wrote.

    2 minutes ago, natureboy said:

    My point is that higher handicap golfers are being penalized more / disproportionately relative to their standard normal dispersion distribution than scratch golfers because of that distance from centerline cutoff. The cutoff falls at a different z-value for higher HCP's than scratch golfers. It's not a huge amount, and may not be enough to justify changing the system, but it's there as an effect.

    That's why slope exists.  Also, as mentioned before, bogey golfers get to consider the trees all along the path of the hole while scratch golfers only get to consider the trees in the landing area.

    And again… if a golfer hits a poor shot 35 yards or more offline, they should be punished by having a higher handicap.


  15. 2 minutes ago, natureboy said:

    That's the 'typical dispersion' for a Bogey Golfer per Broadie. Curiously it is down around the values for Scratch Golfers where this 60 yard window starts to contain the normal distribution of drive dispersion out to 2 sigma.

    Trees in the likely landing area for a significant fraction of a Bogey Golfer's standard distribution of drives seem pretty relevant to this.

    You've missed my point or something… Those golfers who hit the wild drives should be punished for their bigger misses. Making the course rating and/or slope would not punish them as much for terrible shots.


  16. On March 11, 2016 at 0:22 PM, natureboy said:

    I think some 'tree hate' for non-scratch players might be mitigated a bit by a more up to date course rating.

    Course ratings are updated every few years (if the course is a member of their local golf association and/or the USGA).

    On March 11, 2016 at 0:22 PM, natureboy said:

    I think that current USGA course rating system undervalues thick stands  of trees. Their explanation of rating system states that tree composition more than 30 yards from the center line of a hole will have little impact on rating or slope.

    Yeah, 30 yards from the center line of the hole is pretty wide. If you're that bad… why should you deserve to have a really wild tee shot result in a lower handicap? You hit a horrible shot. It should negatively affect (raise) your handicap; the course rating and slope shouldn't be higher. That would let you "get away with" the trees that really aren't in play.

    On March 11, 2016 at 0:22 PM, natureboy said:

    I think this is a somewhat arbitrarily chosen distance arising from a perception of drive dispersion based on course raters' (scratch players) own good swings rather than actual statistics. Jack Nicklaus praised Pinehurst #2 as not having a single tree in play, but there are plenty of holes where I and more skilled, but still 'average' golfers would expect a certain percentage of drives to find the treeline.

    I disagree. Again, if you over-rate the difficulty of hazards, you artificially lower someone's handicap. A scratch golfer doesn't care much about trees 30-35 yards from the center of the fairway. Nor should they.

    Plus, trees > 30 yards away from the centerline aren't ignored, they're just very minimally weighted.

    On March 11, 2016 at 0:22 PM, natureboy said:

    The statistical 1 sigma dispersion for a 12 handicap player who drives 225 yards is about 55 yards wide (22.5 yards on either side of hole center line). That would mean about 2/3 of their drives would be within 22.5 yards of the hole center line. Meanwhile a further 27% of their drives would fall between 22.5 and 55 yards from the center line. That means roughly 1 in 5 drives for a 12 HCP player would end up outside the 60 yard wide 'landing zone' (30 yards on either side of the hole center line) outside of which the USGA doesn't take trees into account for rating purposes.

    So, 2/3 of the time they're totally fine, and the other 1/3 of the time (4-5 times per round) they might be in the trees. Those 4-5 times per round are a big part of the reason why they're a 12 handicap.

    On March 11, 2016 at 0:22 PM, natureboy said:

    Thick woods within a golfer's average drive dispersion might suggest taking less club, but that's automatically less distance and therefore higher score relative to a scratch player who can ignore the tree line. IMO dense trees stands that overlap high HCP driver dispersion can be viewed like an invisible forced carry / layup, and that kind of differential between the scratch and bogey golfer is why the slope rating was created. The thickness of stands between holes matters too, because if it's a thin line of trees chances are the ball will bound to a spot where you can still play down the original or the adjacent fairway, or maybe poke a low one between the trunks. Water hazards have a demarcation line that often if not usually grants some distance on the shot and usually room for a swing and a line of play to the hole or fairway; while dense woods are almost a certain stroke and distance penalty or worse (think Kevin Na's 16 in TX).

    Again, why artificially lower the handicaps of players who hit the ball so far offline that they find trees 30+ yards away from the centerline of the course?

    We already consider the trees along the entire line of play for the bogey rating but only around the landing area for the scratch golfer, so they're already getting somewhat of an "advantage" on that. Why further reduce their handicap for really really poorly played shots?

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