Having always raced boat for boat, I'm curious about handicapping. Lets say you have a boat that is PHRF 57 and one that is PHRF 84. What does one have to do with the other. I know the lower number gives the other one time but how much and what is the method?

Thanks,
Clayton

scratch boat (100) races for 100 minutes, to all be equal the other boats must complete the same course in 57 and 84 minutes.

fast boat does it in 58 minutes, and the slow in 83 mins, then fast boat is third and slow boat 1st (scratch 2nd)

Calcualtion is just a matter of Hcap time = time * rating / 100 to give corrected time.

So if the 57 rated boat sailed a course in 100 minutes then 100*57/100 would be corrected to 57 wouldn't it need to be more than 100 minutes? If the 84 rated boat was sailed really well and its time was also 100 minutes then it would correct out to 84. The boats would tie in head to head racing but the slower boat will lose. Or is my math skills lacking.

Clayton

PHRF is typically used for monohull racing. Dingies and Catamarans use the Portsmouth Handicap System (DPN). PHRF is time on distance; i.e. the longer the course, the more correction the slower boats. They commonly talk in terms of "boat A gets 45 seconds per mile". Portsmouth, on the other hand, is time on time where you simply get a percentage added (or subtracted) to your finish time regardless of how far you sailed. Porsmouth also has the ability to factor in wind strength whereas PHRF does not (to my limited knowledge anyway). Handicap Racing time on distance has never made sense to me.

For more details (including calculation examples) go here: http://www.ussailing.org/portsmouth/

for PHRF go here:http://www.ussailing.org/PHRF/

Hey Clayton,

Like the boy said, PHRF is time-on-distance.

PHRF boat 57 would cover the SAME DISTANCE in 57 minutes
that PHRF boat 84 would cover in 84 minutes.

You can whip out the quick fraction 57/84 which gets about .68, giving you a rough estimate. So, say, you're 84, and you get around the buoys in 40 minutes. the boat 57 would have to give you 1.68 times that number, roughly. So you say 1.68x40, or 67.2. Subtract the diff, which is 27.2.

So, in this instance, boat 57 would have to finish 27.2 minutes faster than you did, at your 40 minutes, to win the race.

I think.

At least that's how I've been understanding the thing...

sea ya
tami

Hi tami,

I think my brain is starting to wrap itself around that concept. Just when I think it starts to make sense it dosen't anymore. So lets try this... if boat A with a rating of 57 runs the course in 2 hrs (120 min) then boat B only needs to best 201 min (3.36 hrs) to correct out? No that is too much... or would you add 32% (1.00-.68) to the time of 120 min and get 158 min? See, I'm really not well.

Clayton

Slightly wrong maths on my part....

Scratch is 100 (1)

Fast(er) boat is 57 (0.57)
other boat is 85 (0.84)

So corrected time (CT) is

CT = elapsed T / (handicap/100)

100 = 100 / (100/100) (100 = 100 * 1)

Fast boat :

CT = 57 / (57 / 100)
= 100

same boat takes one minute longer

CT = 58 / (57/100)
= 101.754386

Same boat takes 56 minutes

CT = 56 / (57 /100)
= 98.24561404


Sorry !

And I am totally confused, because I am still not sure whether Clayton is really intending to ask about Portsmouth, which beachcats use, or PHRF, which bigger boats use, both monohull and (in some areas) multihull.

Clayton, I see you have a Hobie 16, so I think you are probably more interested in how Portsmouth works, rather than PHRF??

Hi Mary,
I also have a Stiletto 27 which normally we race stock (we have 6 at our club). I'm trying to see what would happen if raced against other big multis or even if it can be rated against a mono. It seems I opened a can of worms, but hey, lets go fishing!

Clayton
H16, S27 Not as many as some, but twice as many as most!

In that case, maybe you should contact Jim Frederick and Debbie Schaefer, "summer storm", summer.storm at cros.net. They have managed to get a PHRF system going for the multihulls on the Great Lakes. Lake Erie Multihulls and now, also, Great Lakes Multihulls. They also have managed to get the multihulls admitted to a number of traditionally monohull distance races on the Great Lakes.

PHRF handicapping is usually set up for local fleets that race against each other all the time, because it is based upon relative performance of the boats and skippers. The PHRF ratings for boats in one group may not be interchangeable to use in another area against different boats/skippers. But you can ask Jim or Debbie how they set it up for their area so maybe you can do something similar for your own.

PHRF is a "time on distance" handicap system (although there are now PHRF time on time variants).
http://www.ussailing.com/offshore/hcapsys.htm#PHRF
"The basic time-on-distance formula is: TA = ( D x PHRF ) / 60
TA = Time Allowance in minutes
D = course length in miles
PHRF = rating in seconds per mile
Subtracting the time allowance (TA) from the actual time it took the boat to sail the race (elapsed time or ET) equals the corrected time (CT)."

If two boats race, one with PHRF=57, and one boat with PHRF=84, then the fast boat, sometimes called "scratch boat" (PHRF=57) will have to "give" the slow boat 84-57=27 seconds per mile. So, for a 2.3 mile race, PHRF57 will have to finish 27*2.3=61 seconds ahead of PHRF84, or else he will get 2nd place. In medium size fleets and short races (45-90 minutes), where you know the PHRF numbers of all the boats you are racing against, and you know the race course distance, you can often be 90-95% certain of your handicapped finish, by keeping track of relative finish times of your boat vs others.

For race committee using PHRF (time on distance), it means you must know the exact (rhumbline) distance of race course. This is great for yacht club races around permanent marks.

In contrast, for beachcat races, and dinghy races where marks are set temporarily for more exact windward-leeward configurations, you want a rating system that doesn't care about distance. For these cases, time-on-time, such as Portsmouth, is often used. The disadvantage comes when computing the finishes, which while trivial to a computer, is almost impossible by the competitors. Thus the mantra "one design is where it's at".

And PHRF values are also be used in a time-on-time way...

http://www.ussailing.org/phrf/TOT.htm

Thanks all, I now have enough information for what I need. At least I'll have an idea if racing open handicap.

Clayton