John
Collins
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 doesnt 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).
|
A
|
TCF
= |
------------ |
|
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 rhumb
line boat speed in knots. Here are some commonly used B factors:
B
Factor
|
When
used
|
480
|
Heavy
air or all off the wind |
550
|
"Average"
conditions |
650
|
Very
light air or all windward work |
There
are no hard and fast rules for selecting the B coefficient. Basically,
the lower you select it, the more favorable it will be to the slower
boats.
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:
|
650
|
TCF
= |
------------ |
|
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.
|