Time for Time on Time?

Bookmark and Share

When the starting gun fires for Race 1 of Downeast Race Week 2006, the fleet will not be racing IRC. They tried that in 2005. Then they went back to PHRF, but not scored Time on Distance. Unlike most racers in the USA, these sailors of Maine will be marching to their own drummer, and scoring Time on Time.

Our West Coast editor, Kimball Livingston, reached out to the Mysterious East Coast to find out how this came about. That led to a conversation with Bob Johnstone, regatta chairman for Downeast Race Week 2006.

In 2005, Johnstone reports, “the decision was made to run all events in the Eastern region of the Gulf of Maine under IRC. That included Downeast Race Week and the Mt. Desert Invitational Series of the Northeast Harbor Fleet and the Maine Hospice Regatta. IRC was put forth as the forward-thinking rating rule of the moment with high-profile yacht clubs embracing the concept (see Losing Our Religion in the May issue of SAIL), so the organizing committees were encouraged to support the movement.

"We tried to overcome the difference between the $30 a year for a PHRF rating versus $160-200 annual fee for IRC by offering a '$45 trial IRC certificate program' to encourage participation by boatowners interested in doing only one event”, Johnstone says. Also, part of the hope was that IRC would do a better job of handicapping the traditional centerboard cruising boats so popular in this area (think Hinckley)..

Trophies for 2005 were awarded based on IRC (including some unofficial handicaps that were extrapolated by comparison to similar boats). At the end of the season, participants were supplied with comparative results for the same races, had they been run under PHRF Time-on-Distance and PHRF Time-on-Time. Skippers received these comparative results as part of a survey in a questionnaire that gave them an opportunity to vote on how they wanted to sail in 2006. It was hard not to notice that each handicap system produced different winners.

"What we learned," Johnstone says, "is that a core strength of IRC is its Time-on-Time scoring. TOT seemed to do the fairest job.

"Those who favored staying with IRC for 2006 liked the universality of it. They wanted to give it another year to prove itself, and it's not as though IRC doesn't have promise. However, the voting went strongly in favor of going back to PHRF, but scoring the races Time-on-Time."

Johnstone notes, "One of the assumptions of Time-on-Distance scoring is steady winds.. But the problem is, 75 percent of races are not not in steady winds. In our racing we have lots of start-stop situations because we're going around islands. The races take longer than they would if you sailed the same mileage on windward-leeward courses in a steady breeze. Time-on-Time takes into account all the factors of a race and boils them down to the time spent sailing, which turns out to be a pretty good way to distill the variables of wind velocity, wind angle, and current."

According to the summary drawn up after the annual meeting of the Downeast Race Week committee, which voted to endorse the participant preference:

A) None of the (hoped for benefits of using IRC) were fully met, and US Sailing was unable to convince the RORC to participate in the pilot “trial certificate” program, costing DERW the difference on several boats. Additionally, DERW had to then "assign" ratings to those unable to get ratings in time or unwilling to pay the price for two races.
B) RORC was unwilling to resolve rating anomalies between one-designs of equal sailing weight (J/100s with/without lifelines).
C) IRC didn’t do as good a job of awarding credit for Dacron cruising sails and gennakers as PHRF; this was especially noteworthy in the case of older cruising boats.
D) IRC seemed insensitive to the performance differences between J/100s, J/105s, J/109s and J/35s (rating them almost equally) when solid empirical evidence under PHRF indicated 18-21 seconds per mile performance differences. That one had people scratching their heads."
E) IRC's credits for "recreational" non-exotic sail materials or cruising inventories were less generous than comparable PHRF credits; IRC does not give as generous a credit for cruising gennakers, as it appears to rate primarily area.
F) A questionnaire was sent to all DERW and MDI participants requesting commentary and their choice for a handicapping system to be used in 2006. As background, 2005 results were shown under 3 rating systems, IRC PHRF, and PHRF TOT. 15 of 25 participants responded, with 60% voting for PHRF, 27% for IRC, and 13% indicating "no preference." Of the 11 not voting, 7 would have placed better had the race been scored under PHRF, and 4 would have placed better under IRC.

Those favoring PHRF cited:
Buy American, it's a pain dealing with London
Too many unknowns, too early for IRC
Get rid of inequities in IRC
PHRF has lower annual cost, $30 versus $150, especially significant for just two events
With PHRF crediting cruising sails, it is easier for boats with white sails to compete
IRC does not treat heavy centerboard boats well

Those favoring IRC cited:
Prefer IRC but OK with PHRF TOT; definitely not PHRF TOD
Better to stick with the international community
Having invested, would rather stick with it

Of those responding to the survey who preferred PHRF, 89% expressed a preference for Time on Time scoring.

That ends the summary. Below is an explanation of Time on Time scoring as found on the web site of PHRF New England. Don't miss the bottom line assessment: "TOT scoring is not a cure-all for all the inequities of handicapping. TOT scoring will not turn a fleet upside down. It usually does not affect the top boats. It usually moves the boats in the middle around a little. If the handicap spread in a class is large, it will tend to tighten things up a bit."

From PHRF New England:

The vast majority of handicap racing in North America is scored by the Time on Distance (TOD) method. Here a fixed time allowance, based on the length of the course, is used to compute the corrected time. An advantage of TOD is that is simple and you can tell exactly where you stand at any point in the race. In Europe the Time On Time (TOT) scoring method is popular. Here the time allowance for a given race depends on the time of the race. The reasoning being that smaller boats are at a disadvantage if the race is a slow race if the time allowance doesn't change to account for the conditions of the race. This TOT method is only slightly harder to understand than TOD as the allowance at any point in the race can be affected by a change of conditions later in the race.

Over the past few years a number of PHRF fleets have started using TOT scoring. It has been found to help some when there is a very large handicap spread in a class or if the race conditions are "abnormal". The following is a TOT conversion formula that is commonly used to convert the standard PHRF TOD handicap into a TOT Time Correction Factor (TCF).

TCF = A / (B + PHRF)

The denominator, B + PHRF, is the number of seconds it takes to sail a nautical mile in the expected conditions. Another way to look at it is that the denominator divided into 3600 is the average boat speed in knots. Here are some commonly used B factors:

B Factor
480 in heavy air or if the race is all downwind
550 in average conditions
600 in very light air or if the race is all upwind
The numerator, A, is merely a coefficient that makes a "nice" looking TCF. Select it so that the TCF for the middle of the fleet is about 1.000. The A coefficient has absolutely no effect on the corrected finish order. Changing it will only affect the various margins. Thus if your middle handicap is about 100 and your conditions are average, then the TCF formula would look like the following:

TCF = 650 / (550 + PHRF)

To get the corrected time, simply multiply the elapsed time by the TCF.

TOT scoring is not a cure-all for all the inequities of handicapping. TOT scoring will not turn a fleet upside down. It usually does not affect the top boats. It usually moves the boats in the middle around a little. If the handicap spread in a class is large, it will tend to tighten things up a bit.

  • facebook
  • twitter