Who is using ToT PHRF?

Imagine a PHF system where each boat has a TCF (eg .750) that is applied to the boats elapsed time (in minutes & decimals of a minute). eg 60 minutes X .750 = corrected time of 45 minutes. Faster boat - higher TCF - even greater than 1.000.

It is easy to calculate how much time one owes another boat per hour....

•001 = 3•6 seconds per hour

•01 = 36 seconds per hour

•1 = 6 minutes per hour

A boat wins - TCF goes up, 2nd up not so much down to a point where there is no change, and below that point the TCF is reduced.

Sorta like a golf handicap, but it works. Of course there are always those who whinge about their handicap.

http://www.topyachtsoftware.com/web/

 
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Dawg

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Our club considered switching to ToT a couple of years ago. Ran some test on past races and it didn't make any difference. I think one race had one boat move up. As a competitor, it is nice to know that you need to cover a 3 minute 15 second handicap and not have to calculate it as you would with ToT.
You do realize that in PHRF whether ToD or ToT you are racing the clock and not other boats.

If you can beat your Time Allowance you are going to probably win if other boats do not.

PHRF is a race against the clock.

OD is a race against other boats.

It's like someone said ToT tightens things up a bit where ToD is for those who care about knowing something they cannot really change.

 

allene222

Super Anarchist
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SF Bay
Our club considered switching to ToT a couple of years ago. Ran some test on past races and it didn't make any difference. I think one race had one boat move up. As a competitor, it is nice to know that you need to cover a 3 minute 15 second handicap and not have to calculate it as you would with ToT.
You do realize that in PHRF whether ToD or ToT you are racing the clock and not other boats.

If you can beat your Time Allowance you are going to probably win if other boats do not.

PHRF is a race against the clock.

OD is a race against other boats.

It's like someone said ToT tightens things up a bit where ToD is for those who care about knowing something they cannot really change.
That is just silly.

 

Left Shift

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"An approximation multiplied by another approximation does not increase accuracy." Famous person

ToT may remove course length error made by RCs that haven't entered the GPS era.

ToT will introduce the B factor error, biasing the ratings to one end of the band or the other.

ToT does not handle large rating bands well, especially boats that are toward the end of the rating spectrum (i.e. further from the base boat). The larger boats (minus-raters) in my area typically refused to race ToT events. Then they split off into IRC for different (political) reasons. IRC is ToT of course, so the ToT wasn't the problem, it was how PHRF ToT was not seen as fair on the water.

ToT is NOT easier to use on the water.

ToT is fails miserably when there is significant current or changes in wind strength. ToD has its own issues, of course, but in my view less extreme.

Other parts of the world use rating systems that are built from the ground up to be ToT. PHRF was built from the ground up to be ToD.

Whatever.

Go sailing. Keep it simple. Ask a friend out.

 
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Schnick

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British Columbia uses TOT with a B factor of 520, have since the start. Keep the divisions under 50 seconds, ideally under 30 seconds, apart, works better, but that is true of any PHRF system.

 
G

Guest

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TOD makes no sense at all when courses need to be shortened or wind strength changes noticably
Correct. Its not perfect, but I think ToT is the more flexible of the two methods that accounts for more variables.

 

Left Shift

Super Anarchist
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British Columbia uses TOT with a B factor of 520, have since the start. Keep the divisions under 50 seconds, ideally under 30 seconds, apart, works better, but that is true of any PHRF system.
BC is known to march to its own drummer regarding ratings, and the premier BC event, Southern Straits, is ToD. With rating bands around 30 seconds.

 

Dawg

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Turd Sandwich said:
Large rating bands are the problem and i think they are worse with ToT especially in light air(course takes longer to complete) If you have a rating spread of say 100 seconds plus TOT will favor the slow boat about the same as it favors the the fast boat in TOD in 12 knots of breeze. In the light the fast boat will have to cover almost twice what it would have time wise to cover in TOT in say 5 knots. That does not happen in TOD.

They both suck with large splits. In the light TOT sucks way more for the fast boat.

Tighten up the splits to say 20 or 30 seconds and both do an ok job and its back to horses for courses.

The rise in popularity for TOT comes down to one thing only. The race committee can be lazy fucks with TOT as no distance is required
Interesting points.

With small fleet and wide band, you cannot tighten up the bands unless you want 2 boats in each fleet.

 

SemiSalt

Super Anarchist
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We switched to ToT this year.

I asked myself at what speed around the course would the ToT time corrections be the same (approximately) as for PHRF ToD. Answer: a little over 5 knots. (In fact, the boats have to be even faster because of the extra distance sailing on a beat.) That is way faster than you are ever going to see with "ordinary" boats. So, it appears to me that straight jump to ToT with a B around 550 gives a big lift to the slower boats. And, in fact, a couple boats that had never won anything did win races this year. Hurrah for them. I, on the other hand, had a string of 1st to finishes correct to last.

Our Fleet Captain said he re-scored last season's races using ToT and only one place changed all season. This year it made a huge difference.

 

Tax Man

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Toronto
Lake Ontario uses TOT but they have so completely distorted the individual boat ratings and the TCF formula that you really can't call it PHRF.

This may or may not be related to the fact that most weekend multi-club events in Toronto use IRC (also TOT) for handicap racing.

TOT can actually mean more work for the race committee - if you don't need to worry about measuring distances you just focus on having a square course of appropriate length, even as the conditions change. Moving marks is more work than recording distances.

 

condor

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Sailing a ToT event a few years ago in a fleet with large band of ratings, we were scratch boat.

8 knots or so true wind, so sailing near hull speed. In a race where ToD allowance would have been around 4 minutes, ToT gave an allowance of 9 minutes to the same boat.

Don't be the fast boat.

 

dacapo

Super Anarchist
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our wednesday nights are sailed ToT....LARGE ratings band....I sail on 2 of the faster boat.....can;t win when wind is below 10 kts. (throw in 1.5 kts. of current out in the middle of the river and fuck it all...the slow boats in the fleet all vote for it each year (there are more slow boats than fast boats

 

Go Left

Super Anarchist
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The urge for PHRF committees to jump into ToT has been around for decades. As far as I can tell it was promoted by people with too much time on their hands and only a rudimentary understanding of arithmetic. Or maybe just owners of slow boats. It may all look good on paper, but it is based on false assumptions and bad mathematics. Our local PHRF handbook included a paean to ToT with the curious recommendation to clubs to convert. It was riddled with bad assumptions and most clubs blessedly resisted the urge.

It is true that when an event mimics the conditions used to set the conversion factor and is held in simple sailing conditions (little current and/or few holes) ToT produces results not much different from ToD. Of course not. It is a simple conversion factor of the ToD number in the exact conditions that the ToD rating was based on. Big deal. Get away from that ideal and funny business starts. ToT fails completely large rating bands and for minus rated boats.

Our largish boat fleet (PHRF 24 to -50 at the time) actually donated GPS systems to the RC of a major bouy event when they proposed going to ToT to assure that ToD could be accurately and easily implemented.

 
Problem with ToD is it is completely screwed when there is any current. (and in most places there is some current)

Depending on the current, the distance sailed by small boats can be quite different to that sailed by larger boats.

There seems to be a bit of "we use ToD because we've always used ToD". A reluctance to learn or try something different.

 

Go Left

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Problem with ToD is it is completely screwed when there is any current. (and in most places there is some current)

Depending on the current, the distance sailed by small boats can be quite different to that sailed by larger boats.

There seems to be a bit of "we use ToD because we've always used ToD". A reluctance to learn or try something different.
ToD is not "completely screwed" in current. The negative effect you are suggesting is based on time not distance.

Assuming a W/L course, small and large boats sail both in favorable and unfavorable current. The TIME spent on the race course will be different for small and large boats, so the TIME spent in the current will be different. So the current effect occurs in ToT just as much as ToD. It is actually demonstrative of the ToT problem.

 


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