Is the 200ft below Min Finish Height Rule Working?

On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote:
Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low.

Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently.
UH

On Monday, January 20, 2014 2:21:11 PM UTC-6, wrote:
On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote:

Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low.



Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently.

UH

UH answer is deep -- pay attention.

RC gets two constant demands. One, as in the original post, is to add carefully constructed point carpentry around the finish, with 10 points for this and 20 points for that. The other is to simplify the rules, and especially to make sure pilots don't need to do lots of strategizing and in-air calculations. As you come up with alternatives, make sure they satisfy simplicity and clarity too!

John Cochrane

On Monday, January 20, 2014 1:39:11 PM UTC-8, wrote:

RC gets two constant demands. One, as in the original post, is to add carefully constructed point carpentry around the finish, with 10 points for this and 20 points for that. The other is to simplify the rules, and especially to make sure pilots don't need to do lots of strategizing and in-air calculations. As you come up with alternatives, make sure they satisfy simplicity and clarity too!

John Cochrane

This particular issue has received scores of hours of thought, debate and analysis, including just about every conceivable scenario from the beginning of a final glide (below, at, and above optimal Mc final glide OR best L/D glide to the finish) and every major decision scenario as glides go bad (or don't get better - including able to make the cylinder but not the airport, vice-versa and under different penalty structures) ALSO various lift scenarios (none, less than current Mc, and climb rates all they way down to climbs so slow you are losing speed points faster than you lose penalty points). Zoomies at the edge, terrain in the last 10, 5 and 1 miles to the airport, proximity to a ridge, number of runways, configuration of the approach versus the finish, trees at the end of the runway and number of competitors trying to land at once with how much energy. It ALL gets assessed and debated, including the bizarre potential choices pilots might make (although pilots can be very creative in coming up with bizarre things - the analysis did include low circling to get up to finish height even right up to the edge of the cylinder). Then what gets discussed is which are likely versus unlikely scenarios and which ones are pilot decision issues versus places where the rules beg the pilot to take a chance in order to score more points. LASTLY it all gets put into the filter of don't change anything and make it simple (against the tide of requests for specific exceptions to handle odd cases).

In this case the higher order issues boiled down to: 1) The rules should not be set up to award points to pilots who cross the finish cylinder at an altitude from which it is unlikely that (s)he can safely reach the airport (including scenarios with the runway not lined up, into the wind and with trees), 2) Assess a modest penalty for most common glide gone wrong errors, such that a pilot would not ignore a reasonable-looking climb along the way on a marginal glide to MFH.

If you do the math what you find is if you allow (as we do) different finish heights and different sized finish circles you can end up with not much room between the bottom of the mild penalty and "can't get to the airport" height. A penalty structure that varies the steepness of the penalty depending on the cylinder radius and MFH is possible, but complex and was set aside as was restricting the finish height to 1000' or above as some sites with ridges like the flexibility to finish right off the ridge.

It's mostly documented in the RC notes. I'd be happy to take anyone through the "all the scenarios" analysis offline - there's a lot to think about before you boil it down to a set of simple rules and it's easy to fix one thing while braking something else.

9B

On Monday, January 20, 2014 6:37:18 PM UTC-5, wrote:
On Monday, January 20, 2014 1:39:11 PM UTC-8, wrote:



RC gets two constant demands. One, as in the original post, is to add carefully constructed point carpentry around the finish, with 10 points for this and 20 points for that. The other is to simplify the rules, and especially to make sure pilots don't need to do lots of strategizing and in-air calculations. As you come up with alternatives, make sure they satisfy simplicity and clarity too!



John Cochrane



This particular issue has received scores of hours of thought, debate and analysis, including just about every conceivable scenario from the beginning of a final glide (below, at, and above optimal Mc final glide OR best L/D glide to the finish) and every major decision scenario as glides go bad (or don't get better - including able to make the cylinder but not the airport, vice-versa and under different penalty structures) ALSO various lift scenarios (none, less than current Mc, and climb rates all they way down to climbs so slow you are losing speed points faster than you lose penalty points). Zoomies at the edge, terrain in the last 10, 5 and 1 miles to the airport, proximity to a ridge, number of runways, configuration of the approach versus the finish, trees at the end of the runway and number of competitors trying to land at once with how much energy. It ALL gets assessed and debated, including the bizarre potential choices pilots might make (although pilots can be very creative in coming up with bizarre things - the analysis did include low circling to get up to finish height even right up to the edge of the cylinder). Then what gets discussed is which are likely versus unlikely scenarios and which ones are pilot decision issues versus places where the rules beg the pilot to take a chance in order to score more points. LASTLY it all gets put into the filter of don't change anything and make it simple (against the tide of requests for specific exceptions to handle odd cases).



In this case the higher order issues boiled down to: 1) The rules should not be set up to award points to pilots who cross the finish cylinder at an altitude from which it is unlikely that (s)he can safely reach the airport (including scenarios with the runway not lined up, into the wind and with trees), 2) Assess a modest penalty for most common glide gone wrong errors, such that a pilot would not ignore a reasonable-looking climb along the way on a marginal glide to MFH.



If you do the math what you find is if you allow (as we do) different finish heights and different sized finish circles you can end up with not much room between the bottom of the mild penalty and "can't get to the airport" height. A penalty structure that varies the steepness of the penalty depending on the cylinder radius and MFH is possible, but complex and was set aside as was restricting the finish height to 1000' or above as some sites with ridges like the flexibility to finish right off the ridge.



It's mostly documented in the RC notes. I'd be happy to take anyone through the "all the scenarios" analysis offline - there's a lot to think about before you boil it down to a set of simple rules and it's easy to fix one thing while braking something else.



9B

Clearly there was a big departure from gradual penalty to the land out penalty. Big change that moved the dangerous flying outside the finish cylinder.. Why the land out penalty. I don't think the land out penalty was well thought through.

The land out penalty should be rolled back and gradual penalty should come back if any.

On Monday, January 20, 2014 5:12:21 PM UTC-8, wrote:

Clearly there was a big departure from gradual penalty to the land out penalty. Big change that moved the dangerous flying outside the finish cylinder. Why the land out penalty. I don't think the land out penalty was well thought through.

The land out penalty should be rolled back and gradual penalty should come back if any.

It mostly boils down to whether you believe there should be a significant points benefit for making a finish at an altitude from which it is impossible to reach the airport. That's a powerful incentive to roll the dice. Should winning hinge on betting your glider (and your life) in exchange for points in that way?

The rest is just math - and how low you set MFH.

9B

On Monday, January 20, 2014 9:04:44 PM UTC-5, wrote:
On Monday, January 20, 2014 5:12:21 PM UTC-8, wrote:



Clearly there was a big departure from gradual penalty to the land out penalty. Big change that moved the dangerous flying outside the finish cylinder. Why the land out penalty. I don't think the land out penalty was well thought through.



The land out penalty should be rolled back and gradual penalty should come back if any.



It mostly boils down to whether you believe there should be a significant points benefit for making a finish at an altitude from which it is impossible to reach the airport. That's a powerful incentive to roll the dice. Should winning hinge on betting your glider (and your life) in exchange for points in that way?



The rest is just math - and how low you set MFH.



9B

You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.

You did not address any problem you just moved the problem somewhere else.

You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.

The point of scoring low finishes as a landout is real simple. When you're deciding "shall I land in the last good field or press on" at MacCready 0 plus 50 feet, it needs to be crystal clear that you will gain nothing by pressing on. This is not safety legislation -- points are off the table, make a good decision, points are the same either way. With a graduated penalty there is always some benefit to pressing on. And complexity. Didn't you guys want simple rules? Try figuring out the points to finish 397 feet low.

It just moves the hard ground down. You used to be scored as a landout -- with none of this mollycoddling graduated penalties -- if you missed the fence by a foot.

Don't think of it as a "penalty." The task is to start below (say) 5000', get inside three turnpoints, and finish no less than (say) 700'. If you didn't do that, you didn't fly the same race as everyone else. In what other sport can you miss the finish line by 200 feet and still get a "finish?" And want more?

John Cochrane

On Monday, January 20, 2014 6:42:14 PM UTC-8, wrote:

You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.

The reason and logic and review and deliberation is in the RC meeting notes.. To recap:

Logical reason is you should not present competitors with a situation where they can score higher points by deciding to go for the finish cylinder at an altitude from which they cannot reach the airport.

You are correct, you could set (based on current rules for max distance from the airport and max radius of the finish cylinder) a mandatory MFH of around 1250' and a graduated penalty of around a point per foot. If you force a smaller, closer finish cylinder you can bring MFH down a bit, but there are serious objections to a higher MFH based on airport configuration, proximity to ridge, etc.

Again, If this explanation doesn't suffice I'd be happy to walk anyone through the math and logic offline.

9B