Virtually Certain - some maths

[Foxholer]

Your correct Foxy , the brandy thinks , maybe you should change your avatar from Fox to Ass suits you better .:rofl:

:rofl:

Been done elsewhere apparently! Fits in with the 'shairn' reference too!

Never quite got the 'hang' of Brandy. For a 'digestif' it has the opposite effect on me!

 

[3565]

This thread is waaaaaaaayyyyyyy above my head.

By sounds of it you lot could decifer The Golfing Machine book by Homer Kelley?

 

[drdel]

Except 2 Standard Deviations/95% is only 'very probably'! Almost certain (99.7%) (and maybe sufficient for 'virtually certain') would be 3SDs! Bayes Theory/Rule/Law would still apply - the numbers (probabilities) would simply be different.

@ColinL What did you say the Gaelic/Scots was for Cow Poo again? :rofl:

OK Foxholer I'll take the bait.

With subjective judgements like that you're obviously not a very good and successful gambler ! Anyone offering me a 95% probability of a win would make me 'virtually' certain I'd get my winnings. Regarding Bayes - you're wrong because the events do not have any sort of random result. The golfer will know his shot length and whether the will normally fall short or reach the water whereas Bayes' mathematics relies on randomness.

I've now lost the will to live to over to you for the last word.

 

[atticusfinch]

Aren't you talking about two entirely different certainties? One, the certainty that some event will occur and how likely that is to happen based on the maths. The gambler's task. Expressed as odds...eg one in ten chances this will be the result.

The other is the certainty that something is factually true. Whether it has occurred. That is not a predictive task based on statistics, it is an evidentiary matter based on the existence of known facts, the reasonable inferences they lead to and how likely the sought fact is to be true. considering all the evidence.

It's not the chance maths a gambler uses, it is the weight of evidence maths a fact finder uses. The golf rules people use numbers like 98% certainty to express the almost certain truth the rules demand. Beyond a reasonable doubt is also an expression of the high standard necessary. Both are helpful to express the importance of the standard, but in the final analysis only "virtual certainty" (as explained in dec 26-1/1) of a fact will suffice.

 

[daymond]

My take on this is that if the ball is not found in the area, both water and grass, in the five minutes allowed, it's deemed lost in the hazard.

 

[Colin L]

My take on this is that if the ball is not found in the area, both water and grass, in the five minutes allowed, it's deemed lost in the hazard.

It is only considered lost in the water hazard if you know it is or are virtually certain it is in the hazard in which case Rule 26 applies. Otherwise, it is just plain lost and Rule 27 applies.

To understand what virtual certainty is, I refer you to the mathematicians above. :rofl:

 

[SammmeBee]

My take on this is that if the ball is not found in the area, both water and grass, in the five minutes allowed, it's deemed lost in the hazard.

The fact you've looked outside the hazard would strongly suggest you cannot be virtually certain it can only be in the hazard....

 

[atticusfinch]

The fact you've looked outside the hazard would strongly suggest you cannot be virtually certain it can only be in the hazard....

Doesn't not finding it in the grass reinforce the certainty it is in the water?

I have heard that argument before: if you are certain it is in the water, why look elsewhere? That position ignores the fact that knowing where it IS can be enhanced by knowing where it ISN'T.

Only if you had to establish VC immediately would not searching in grass make any sense.

 

[delc]

Doesn't not finding it in the grass reinforce the certainty it is in the water?

I have heard that argument before: if you are certain it is in the water, why look elsewhere? That position ignores the fact that knowing where it IS can be enhanced by knowing where it ISN'T.

Only if you had to establish VC immediately would not searching in grass make any sense.

I note that the rules of golf do not define 'virtually certain'! If you find your marked ball in the water hazard, or in the long grass, then you are 100% certain of its position, but if you can't find it there is always some degree of uncertainty. At our course most of our water hazards are at least partly hidden from the tees, so this issue comes up all the time. One water hazard is completely hidden, so we have the special local rule on that hole only which allows you to play a 2nd ball provisionally, even if you are pretty sure from the length and trajectory that the original ball has gone in. The specimen local rule reads:

If a water hazard (including a lateral water hazard) is of such size and shape and/or located in such a position that:
(i) it would be impracticable to determine whether the ball is in the hazard or to do so would unduly delay play, and
(ii) if the original ball is not found, it is known or virtually certain that it is in the water hazard,
the Committee may introduce a Local Rule permitting the play of a ball provisionally under Rule 26-1. The ball is played provisionally under any of the applicable options under Rule 26-1 or any applicable Local Rule. In such a case, if a ball is played provisionally and the original ball is in a water hazard, the player may play the original ball as it lies or continue with the ball played provisionally, but he may not proceed under Rule 26-1 with regard to the original ball.
In these circumstances, the following Local Rule is recommended:

“If there is doubt whether a ball is in or is lost in the water hazard (specify location), the player may play another ball provisionally under any of the applicable options in Rule 26-1.
If the original ball is found outside the water hazard, the player must continue play with it.
If the original ball is found in the water hazard, the player may either play the original ball as it lies or continue with the ball played provisionally under Rule 26-1.
If the original ball is not found or identified within the five-minute search period, the player must continue with the ball played provisionally.
PENALTY FOR BREACH OF LOCAL RULE:
Match play – Loss of hole; Stroke play – Two strokes.”

 

[chrisd]

I don't get the need for a local rule. If it known or virtually certain to have gone into a water hazard then you proceed under rule 26, if you don't know or its NOT virtually certain to be in the water hazard you play a provisional or go back to the tee if you don't find it - it's pretty simple and doesn't need a local rule for me

 

[chrisd]

Doesn't not finding it in the grass reinforce the certainty it is in the water?

I have heard that argument before: if you are certain it is in the water, why look elsewhere? That position ignores the fact that knowing where it IS can be enhanced by knowing where it ISN'T.

Only if you had to establish VC immediately would not searching in grass make any sense.

I agree, virtual certainty suggests a degree of uncertainty that a look in the grass either, helps confirm or otherwise, the decision

 

[delc]

I don't get the need for a local rule. If it known or virtually certain to have gone into a water hazard then you proceed under rule 26, if you don't know or its NOT virtually certain to be in the water hazard you play a provisional or go back to the tee if you don't find it - it's pretty simple and doesn't need a local rule for me

The special local rule applies on a long par-3 hole with a water hazard in a dip on the right hand side that is not visible from the tee, so it's difficult to know or be virtually certain that the ball has gone in. It's a hole that often causes hold ups when the course is busy, so playing a provisional ball helps to save time, by not having to walk back if you can't account for the original ball. Seems like a good idea to me!

P.S. You can't normally play a provisional ball if it's KVC that the original ball is in a water hazard.

 

[rickg]

Del is that an approved local rule or did the club just make it up themselves. Most local rules have guidance on how they should be worded in one of the Appendixes in the rule book.

 

[delc]

Del is that an approved local rule or did the club just make it up themselves. Most local rules have guidance on how they should be worded in one of the Appendixes in the rule book.

Rick. If you read back a few posts, I have already quoted the relevant specimen local rule from Appendix I, Part B of the R&A Rules of Golf.

 

[duncan mackie]

The special local rule applies on a long par-3 hole with a water hazard in a dip on the right hand side ..... so playing a provisional ball helps to save time, by not having to walk back if you can't account for the original ball. Seems like a good idea to me!

P.S. You can't normally play a provisional ball if it's KVC that the original ball is in a water hazard.

this doesn't make sense

1. this LR should only be in place if a ball not found in that area is K or VC that it's in the hazard
2 most club golfers would rather play from closer to the green (under 26-1) than play again from the tee at a long par 3.

this LR is primarily designed for situations where a ball may, or may not have carried a water hazard but because the far margin and landing area are not visible from the tee (or fairway) uncertainly exists until the players have walked all the way to the other side and can see the landing area properly.

 

[drdel]

Oh gawd - now the "rules gurus are flying in - here was I think the OP was just having a bit of fun and banter with numbers loosely related to a golf situation.

 

[delc]

this doesn't make sense

1. this LR should only be in place if a ball not found in that area is K or VC that it's in the hazard
2 most club golfers would rather play from closer to the green (under 26-1) than play again from the tee at a long par 3.

this LR is primarily designed for situations where a ball may, or may not have carried a water hazard but because the far margin and landing area are not visible from the tee (or fairway) uncertainly exists until the players have walked all the way to the other side and can see the landing area properly.

The water hazard in question is completely hidden from the tee. Under the specimen local rule you can play a provisional ball under any of the options in Rule 26-1 including from the tee. To quote:

“If there is doubt whether a ball is in or is lost in the water hazard (specify location), the player may play another ball provisionally under any of the applicable options in Rule 26-1.
If the original ball is found outside the water hazard, the player must continue play with it.
If the original ball is found in the water hazard, the player may either play the original ball as it lies or continue with the ball played provisionally under Rule 26-1.
If the original ball is not found or identified within the five-minute search period, the player must continue with the ball played provisionally."

 

[duncan mackie]

The water hazard in question is completely hidden from the tee. Under the specimen local rule you can play a provisional ball under any of the options in Rule 26-1 including from the tee. To quote:

“If there is doubt whether a ball is in or is lost in the water hazard (specify location), the player may play another ball provisionally under any of the applicable options in Rule 26-1.
If the original ball is found outside the water hazard, the player must continue play with it.
If the original ball is found in the water hazard, the player may either play the original ball as it lies or continue with the ball played provisionally under Rule 26-1.
If the original ball is not found or identified within the five-minute search period, the player must continue with the ball played provisionally."

absolutely none of which has any relevance to your statement " not having to walk back if you can't account for the original ball. Seems like a good idea to me!"

if you play another ball from the tee as a provisional it becomes your sole 26-1 option if the ball is in the hazard - in the situation described this doesn't seem a great option to take.

 

[delc]

absolutely none of which has any relevance to your statement " not having to walk back if you can't account for the original ball. Seems like a good idea to me!"

if you play another ball from the tee as a provisional it becomes your sole 26-1 option if the ball is in the hazard - in the situation described this doesn't seem a great option to take.

Yes but if you find your original ball outside the hazard (or in it if playable) you just play that. The problem with this particular water hazard is that it is completely hidden from the tee, so it is impossible to know or be virtually certain that a ball has gone into it. That is the whole point of this local rule, and I presume that our club committee felt it was necessary to invoke it.

P.S. As you can't KVC that the ball is in the water hazard in this case, if you couldn't find the original ball it would be lost and then you would definitely have to go back and play 3 off the tee!

 

[drdel]

^^^ We know from the extensive commentary here and the heat generated by the discussions about slow play - that perhaps, between sensible golfers (all whom are of course, gentlemen and ladies) playing a provisional ball is, occasionally, the sensible just-in-case option to avoid delaying play by having to return to the Tee; even when the Rules require it (exc competitions).