As we run handicap racing and sailwave to work out the results I am puzzled when we get a tie. Can sailwave work out corrected times to 2 or 3 decimal places? When we get a tie say 2 people equal 2nd why does it give them 3 points each in stead of 2
ta
Mike
Go to Scoring System and make sure you have “ISAF Appendix A standard low point” checked
S. Mark Townsend
Phone: 562-433-4366
Cell: 562-533-5909
Email: s_mark_townsend@hotmail.com
···
From: sailwave@yahoogroups.com [mailto:sailwave@yahoogroups.com] On Behalf Of mikerigg@ymail.com
Sent: Sunday, December 11, 2011 10:59 AM
To: sailwave@yahoogroups.com
Subject: [sailwave] Race Ties
As we run handicap racing and sailwave to work out the results I am puzzled when we get a tie. Can sailwave work out corrected times to 2 or 3 decimal places? When we get a tie say 2 people equal 2nd why does it give them 3 points each in stead of 2
ta
Mike
I’m sure it can, but how accurate were the original times? Probably not ‘that’ accurate, so why split hairs when a tie would be a fairer result?
HTH
Mike
Lancing SC
···
— In sailwave@yahoogroups.com, “mikerigg@…” <mikeandmaggierigg@…> wrote:
As we run handicap racing and sailwave to work out the results I am puzzled when we get a tie. Can sailwave work out corrected times to 2 or 3 decimal places?
Extending Mike C’s point, PYR handicaps are accurate at best to 1 part in 1000, so in a one hour race that’s 6 seconds. Recently the RYA changed the PYR of the venerable and much sailed Laser by 4, i.e 24 seconds. Compared to an RS200 the Laser moved 36 seconds - that time difference covers a quarter of the fleet in some races. Where’s your 0.23 sec time difference now?
The simple fact is, handicap racing is very approximate (unless the tied boats are in the same class, but I lost that argument here a few months ago).
More to the point, where in Sailwave can Mike R control whether two boats tied for 2nd place score 2 points each, 3 points each or 2.5 points each. I know its there somewhere…
Ian.
···
On 12 December 2011 09:45, Mike mike.croker@phonecoop.coop wrote:
— In sailwave@yahoogroups.com, “mikerigg@…” <mikeandmaggierigg@…> wrote:
As we run handicap racing and sailwave to work out the results I am puzzled when we get a tie. Can sailwave work out corrected times to 2 or 3 decimal places?
I’m sure it can, but how accurate were the original times? Probably not ‘that’ accurate, so why split hairs when a tie would be a fairer result?
HTH
Mike
Lancing SC
I had an instance when two boats of the same class were separated by 1 second on the water. After calculating the results and applying the same handicap Sailwave gave them the same corrected time (I assume because of rounding errors) and scored a tie. I was surprised. I increased the time of the second boat by a second which removed the tie.
William Redman (Chair - Yorkshire and Humberside Youth Sailing Association)
···
From: Ian Savell iansavell@gmail.com
To: sailwave@yahoogroups.com
Sent: Monday, 12 December 2011, 10:30
Subject: Re: [sailwave] Re: Race TiesExtending Mike C’s point, PYR handicaps are accurate at best to 1 part in 1000, so in a one hour race that’s 6 seconds. Recently the RYA changed the PYR of the venerable and much sailed Laser by 4, i.e 24 seconds. Compared to an RS200 the Laser moved 36 seconds - that time difference covers a quarter of the fleet in some races. Where’s your 0.23 sec time difference now?
The simple fact is, handicap racing is very approximate (unless the tied boats are in the same class, but I lost that argument here a few months ago).
More to the point, where in Sailwave can Mike R control whether two boats tied for 2nd place score 2 points each, 3 points each or 2.5 points each. I know its there somewhere…
Ian.
On 12 December 2011 09:45, Mike mike.croker@phonecoop.coop wrote:
— In sailwave@yahoogroups.com, “mikerigg@…” <mikeandmaggierigg@…> wrote:
As we run handicap racing and sailwave to work out the results I am puzzled when we get a tie. Can sailwave work out corrected times to 2 or 3 decimal places?
I’m sure it can, but how accurate were the original times? Probably not ‘that’ accurate, so why split hairs when a tie would be a fairer result?
HTH
Mike
Lancing SC
Our club has a calculator designed for use with money. It rounds everything up or down to 2 places of decimals. If, in the course of working out the results, you at some stage multiply by 1000 (as you do) you can get an error of 10 seconds!
Rgds
George
···
----- Original Message -----
From:
WILLIAM REDMAN
Sent: Monday, December 12, 2011 11:44 AM
Subject: Re: [sailwave] Re: Race Ties even when not tied
I had an instance when two boats of the same class were separated by 1 second on the water. After calculating the results and applying the same handicap Sailwave gave them the same corrected time (I assume because of rounding errors) and scored a tie. I was surprised. I increased the time of the second boat by a second which removed the tie.
William Redman (Chair - Yorkshire and Humberside Youth Sailing Association)
From: Ian Savell iansavell@gmail.com
To: sailwave@yahoogroups.com
Sent: Monday, 12 December 2011, 10:30
Subject: Re: [sailwave] Re: Race TiesExtending Mike C's point, PYR handicaps are accurate at best to 1 part in 1000, so in a one hour race that's 6 seconds. Recently the RYA changed the PYR of the venerable and much sailed Laser by 4, i.e 24 seconds. Compared to an RS200 the Laser moved 36 seconds - that time difference covers a quarter of the fleet in some races. Where's your 0.23 sec time difference now? The simple fact is, handicap racing is very approximate (unless the tied boats are in the same class, but I lost that argument here a few months ago). More to the point, where in Sailwave can Mike R control whether two boats tied for 2nd place score 2 points each, 3 points each or 2.5 points each. I know its there somewhere...Ian.
On 12 December 2011 09:45, Mike mike.croker@phonecoop.coop > > wrote:
— In sailwave@yahoogroups.com , “mikerigg@…” <mikeandmaggierigg@…> wrote:
As we run handicap racing and sailwave to work out the results I am puzzled when we get a tie. Can sailwave work out corrected times to 2 or 3 decimal places?
I'm sure it can, but how accurate were the original times? Probably not 'that' accurate, so why split hairs when a tie would be a fairer result?
HTH
Mike
Lancing SC
The concept of rounding, at least from a scientific point of view, is to neither create nor discard data. If you time something to the nearest second then at the end of your calculations you don't want a result that presents an accuracy of less than one second. By the same token, if you take times in hundredths of a second you wouldn't want to round to the nearest second and throw away the significant digits that you actually measured.
I believe the standard rule is to round the final results of a calculation (not the intermediate steps) using the least significant digit of the numbers used in the calculations. For example, with TOD scoring - if miles are in tenths (e.g., 2.4) and times are in seconds 1503) then the final correction factor (and resulting corrected times) should be in whole seconds since the least significant digit of your measurements was whole seconds. Similarly, if you measured time in hundredths of a second but miles to only tenths then the final result should be rounded to tenths of a second (your least significant digit being tenths of a mile).
Think about IRC Time Correction Factors for a minute - I understand they go to three decimal places. For a one hour race (3600 seconds) that is an accuracy of +/- 3.6 seconds. In that context, rounding corrected times in seconds to two or three decimal places is somewhat absurd. It does break ties but presumably on a random basis. If you don't want race ties (not sure why that would be) then from a transparency viewpoint it would probably be better to break ties at the whole-second level the way the team racing appendix in the rulebook provides - a game of chance, like flipping a coin or drawing high card. That way it is clear to everyone that it is random and not based on skill.
The rulebook has a provision on how to score race ties so it certainly contemplates them (add the scores for the places that are tied and divide by the number of tied boats). Personally, I would round all corrected times to the accuracy with which the finish times were taken (typically the nearest whole second) and leave any remaining ties. My experience is race ties give both tied competitors a reason to smile and are therefore not generally considered a negative. [Series ties are a different matter.] If you want to break race ties then I think you need to say something in your SIs (and NOR) since breaking race ties isn't covered in the rulebook. You probably don't need to mention your rounding conventions so long as they are the same for every race AND you always display them (i.e., if you arbitrarily break ties at the tenth of a second level then ALL your corrected times should be displayed to tenths of a second).
Art
···
On 12/12/2011 1:45 AM, Mike wrote:
--- In sailwave@yahoogroups.com, "mikerigg@..."<mikeandmaggierigg@...>
wrote:As we run handicap racing and sailwave to work out the results I am
puzzled when we get a tie. Can sailwave work out corrected times to 2 or
3 decimal places?I'm sure it can, but how accurate were the original times? Probably not
'that' accurate, so why split hairs when a tie would be a fairer
result?HTHMikeLancing SC
The 2001-2004 Racing Rules of Sailing in rule A3 included statement “corrected to the nearest second”. This was removed in the 2005-2008 rules and was left to the individual handicap systems to determine level of precision.
RRS 2001-2004
A3 STARTING TIMES AND FINISHING PLACES
The time of a boat’s starting signal shall be her starting time, and the order in
which boats finish a race shall determine their finishing places. However, when
a handicap system is used a boat’s elapsed time, corrected to the nearest
second, shall determine her finishing place.
RRS 2005-2008
A3 STARTING TIMES AND FINISHING PLACES
The time of a boat’s starting signal shall be her starting time, and
the order in which boats finish a race shall determine their finishing
places. However, when a handicap or rating system is used a boat’s
corrected time shall determine her finishing place.
S. Mark Townsend
Phone: 562-433-4366
Cell: 562-533-5909
Email: s_mark_townsend@hotmail.com
···
From: sailwave@yahoogroups.com [mailto:sailwave@yahoogroups.com] On Behalf Of Art Engel
Sent: Monday, December 12, 2011 3:47 PM
To: sailwave@yahoogroups.com
Subject: Re: [sailwave] Re: Race Ties
The concept of rounding, at least from a scientific point of view, is to
neither create nor discard data. If you time something to the nearest
second then at the end of your calculations you don’t want a result that
presents an accuracy of less than one second. By the same token, if you
take times in hundredths of a second you wouldn’t want to round to the
nearest second and throw away the significant digits that you actually
measured.
I believe the standard rule is to round the final results of a
calculation (not the intermediate steps) using the least significant
digit of the numbers used in the calculations. For example, with TOD
scoring - if miles are in tenths (e.g., 2.4) and times are in seconds
1503) then the final correction factor (and resulting corrected times)
should be in whole seconds since the least significant digit of your
measurements was whole seconds. Similarly, if you measured time in
hundredths of a second but miles to only tenths then the final result
should be rounded to tenths of a second (your least significant digit
being tenths of a mile).
Think about IRC Time Correction Factors for a minute - I understand they
go to three decimal places. For a one hour race (3600 seconds) that is
an accuracy of +/- 3.6 seconds. In that context, rounding corrected
times in seconds to two or three decimal places is somewhat absurd. It
does break ties but presumably on a random basis. If you don’t want race
ties (not sure why that would be) then from a transparency viewpoint it
would probably be better to break ties at the whole-second level the way
the team racing appendix in the rulebook provides - a game of chance,
like flipping a coin or drawing high card. That way it is clear to
everyone that it is random and not based on skill.
The rulebook has a provision on how to score race ties so it certainly
contemplates them (add the scores for the places that are tied and
divide by the number of tied boats). Personally, I would round all
corrected times to the accuracy with which the finish times were taken
(typically the nearest whole second) and leave any remaining ties. My
experience is race ties give both tied competitors a reason to smile and
are therefore not generally considered a negative. [Series ties are a
different matter.] If you want to break race ties then I think you need
to say something in your SIs (and NOR) since breaking race ties isn’t
covered in the rulebook. You probably don’t need to mention your
rounding conventions so long as they are the same for every race AND you
always display them (i.e., if you arbitrarily break ties at the tenth of
a second level then ALL your corrected times should be displayed to
tenths of a second).
Art
On 12/12/2011 1:45 AM, Mike wrote:
— In sailwave@yahoogroups.com, “mikerigg@…”<mikeandmaggierigg@…>
wrote:As we run handicap racing and sailwave to work out the results I am
puzzled when we get a tie. Can sailwave work out corrected times to 2 or
3 decimal places?I’m sure it can, but how accurate were the original times? Probably not
‘that’ accurate, so why split hairs when a tie would be a fairer
result?HTHMikeLancing SC
Mark is correct. The phrase "corrected to the nearest second" was removed from A3 specifically because rounding to the nearest second would not be appropriate if you took finish times with a greater accuracy (say to the nearest tenth of a second or hundredth of a minute). The idea was that rating and handicap systems should specify a recommended level of precision or in the absence of a recommendation the scientific rounding rules would be applied. Unfortunately, I don't think rating and handicap systems have acted and the scientific rounding rules don't seem to be well understood or generally followed (if they were, then we wouldn't be having this discussion!).
I am not sure but I think that after the 2005 change most scoring programs left the rounding to be whole seconds when the input finish times were in whole seconds. However, some certainly did change they way they rounded, allowing two or three decimal places in corrected times - certainly inappropriate in terms of the standard rounding rules but not in violation of the rulebook per se. Consistency and transparency are probably all that are required to comply with the rulebook although I think good scoring practice would be to apply the standard rounding rules.
Art
···
On 12/12/2011 4:11 PM, S Mark Townsend wrote:
The 2001-2004 Racing Rules of Sailing in rule A3 included statement
"corrected to the nearest second". This was removed in the 2005-2008 rules
and was left to the individual handicap systems to determine level of
precision.RRS 2001-2004
A3 STARTING TIMES AND FINISHING PLACES
The time of a boat's starting signal shall be her starting time, and the
order inwhich boats finish a race shall determine their finishing places. However,
whena handicap system is used a boat's elapsed time, corrected to the nearest
second, shall determine her finishing place.
RRS 2005-2008
A3 STARTING TIMES AND FINISHING PLACES
The time of a boat's starting signal shall be her starting time, and
the order in which boats finish a race shall determine their finishing
places. However, when a handicap or rating system is used a boat's
corrected time shall determine her finishing place.
S. Mark Townsend
Phone: 562-433-4366Cell: 562-533-5909
Email:<mailto:s_mark_townsend@hotmail.com> s_mark_townsend@hotmail.com
My experience is race ties give both tied competitors a reason to smile and
are therefore not generally considered a negative.
Agree: the only ‘problem’ is when the race team split ‘ties’ by going to the nth decimal place using manual calculations before the SW computed results have been done :~
Seems that the calculation precision should be specified in the SIs.
PHRF uses a single rating coefficient to correct elapsed times based on course length and is referred to as a time on distance correction. PHRF corrected times are calculated using the following equation:
corrected = elapsed - (R * d) (1)
where R is the PHRF rating of the boat in seconds per nautical mile (sec/nm) and d (for distance) is the straight line length of the course in nautical miles. For example, suppose that a J35 with PHRF rating
R = 72 sec/nm completes a 10.1nm course in 7200 seconds (2 hours) and a Farr 40 with a PHRF rating R = 0 sec/nm completes the same course in 6473 seconds. the corrected times would be as follows.
J35 corrected = 7200sec - (72sec/nm*10.1nm) = 6472.8 seconds
Farr 40 corrected = 6504sec - (0sec/nm*10.1nm) = 6473 seconds
The corrected time is being calculated to the precision of course distance. IRC, ORC-Club, Portsmouth specify that the Corrected Time shall be rounded to the closest second. PHRF is alone in not specifying officially what is required and leaving the specification to the SIs. Appendix L doesn’t give any guidance as to what words should be used so by default nothing is normally said, and the precision should remain.
Does it make sense, maybe not. If you want PHRF corrected to the nearest second state so in your NOR and SI’s.
···
To: sailwave@yahoogroups.com
From: mike.croker@phonecoop.coop
Date: Tue, 13 Dec 2011 09:45:09 +0000
Subject: [sailwave] Re: Race Ties
— In sailwave@yahoogroups.com, Art Engel <artengel123@…> wrote:
My experience is race ties give both tied competitors a reason to smile and
are therefore not generally considered a negative.
Agree: the only ‘problem’ is when the race team split ‘ties’ by going to the nth decimal place using manual calculations before the SW computed results have been done :~
Seems that the calculation precision should be specified in the SIs.
Mike
Lancing SC
I’m certain that the PY system specifies rounding to 1 second - see the RYA YR2 book. The notice of race for any open event needs to specify the handicap system to be used and I guess for club races the sailing instructions should do so as there probably isn’t an associated RN.
As someone has already said we are only recording finish times to the nearest second and even that depends on how quickly the recorder reacts to the boat finishing, so we should not expect to state corrected times to any greater accuracy than the accuracy of the original data; i.e. nearest second. Separating close finishing boats of the same class had to be done pragmatically by adding or deducting a second to/from one or the other; they will have been recorded as 1 or 2 seconds apart anyway.
Richard
Chanonry SC
www.chanonry.org.uk
···
On Dec 13, 2011 9:45 AM, “Mike” mike.croker@phonecoop.coop wrote:
— In sailwave@yahoogroups.com, Art Engel <artengel123@…> wrote:
My experience is race ties give both tied competitors a reason to smile and
are therefore not generally considered a negative.Agree: the only ‘problem’ is when the race team split ‘ties’ by going to the nth decimal place using manual calculations before the SW computed results have been done :~
Seems that the calculation precision should be specified in the SIs.Mike
Lancing SC
A good recitation of the applicable issues but I don't think your conclusion is correct. The rulebook makes no mention of rounding. Therefore, both rounding and not rounding would comply with A3, which only specifies "corrected times."
I think the argument that you make is based on the premise that the RC can only do what is authorized by the rulebook and nothing else. I don't think that is true. An overriding assumption of the rulebook is that the RC has wide authority to run fair races so long as they don't do anything prohibited by the rulebook. If something isn't prohibited then the RC can generally do it so long as it acts consistently and what it does isn't fundamentally unfair to all or some competitors. To cover every possible contingency and issue the RC might face we would need a rulebook that is hundreds, if not thousands, of pages long; that would be unworkable. The rulebook doesn't prohibit any one particular method of calculating corrected times so I believe you can use any reasonable method so long as it is done consistently and is basically fair. Rounding corrected times to the nearest second clearly meets that standard so is OK under the rulebook (AND, not rounding would I think be OK as well although there is a better argument that not rounding would not be "fair" because it violates the general rules on rounding and significant digits calculations).
I'd be curious for the rule citations for IRC, ORC-Club and Portsmouth as I wasn't aware the rules for those organizations actually specified rounding to the nearest second. Unfortunately, there is no national organization for PHRF (it is a bunch of different local sailors for each place) so even if "PHRF" wanted to adopt a national rounding rule they couldn't.
Art
PS - Several folks proposed mentioning rounding in the SIs so the scorers won't goof it up by not rounding. That would be OK. The policy needs to be the same from race to race. You could do that with a scoring manual or an instruction sheet for the scorers or a statement in the SIs or some other way - your choice. Most scoring programs automatically do one or the other (but not both) so I would simply leave it up to the scoring program to do the same thing every time. The important thing is that folks who score are often more computer-savvy than sailing-savvy and so may need instructions or other help to be sure they do it correctly under the system in use.
···
On 12/13/2011 6:15 AM, Mark Townsend wrote:
PHRF uses a single rating coefficient to correct elapsed times based on course length and is referred to as a time on distance correction. PHRF corrected times are calculated using the following equation:
corrected = elapsed - (R * d) (1)
where R is the PHRF rating of the boat in seconds per nautical mile (sec/nm) and d (for distance) is the straight line length of the course in nautical miles. For example, suppose that a J35 with PHRF rating
R = 72 sec/nm completes a 10.1nm course in 7200 seconds (2 hours) and a Farr 40 with a PHRF rating R = 0 sec/nm completes the same course in 6473 seconds. the corrected times would be as follows.J35 corrected = 7200sec - (72sec/nm*10.1nm) = 6472.8 seconds
Farr 40 corrected = 6504sec - (0sec/nm*10.1nm) = 6473 seconds
The corrected time is being calculated to the precision of course distance. IRC, ORC-Club, Portsmouth specify that the Corrected Time shall be rounded to the closest second. PHRF is alone in not specifying officially what is required and leaving the specification to the SIs. Appendix L doesn't give any guidance as to what words should be used so by default nothing is normally said, and the precision should remain.
Does it make sense, maybe not. If you want PHRF corrected to the nearest second state so in your NOR and SI's.
To: sailwave@yahoogroups.com
From: mike.croker@phonecoop.coop
Date: Tue, 13 Dec 2011 09:45:09 +0000
Subject: [sailwave] Re: Race Ties--- In sailwave@yahoogroups.com, Art Engel<artengel123@...> wrote:
My experience is race ties give both tied competitors a reason to smile and
are therefore not generally considered a negative.Agree: the only 'problem' is when the race team split 'ties' by going to the nth decimal place using manual calculations before the SW computed results have been done :~ Seems that the calculation precision should be specified in the SIs.MikeLancing SC
The effective limit on what the RC (including the Scorer) can do is
set by rule 62.1. Redress can be granted if it s demonstrated that
an improper action or omission of the RC significantlymade worse a
boat’s score, through no fault of her own. This allows the RC a lot
of latitude!
A claim that rounding up or down significantly made a boat's score
worse would make for an interesting hearing.
Gordon
···
<artengel123@…>