HC1. Definitions

In sailing "handicap" is a rather broadly defined term which encompasses a variety of adjustment factors applied to the "Elapsed Time" of a Competitor in a race.

There are two types of adjustment factors.

1. those that define the design & built of the boat
   The Darwin Sailing Club (DSC) uses
   • Yardsticks for off the beach dinghies and cats
   • and AMS values for keelboats and trailables
   
   
   
2. and those that reflect (or include) the performance of Skipper & Crew
   The DSC uses
   • Personal handicaps for off the beach dinghies and cats
   • and Performance handicaps for keelboats and trailables

HC2. Off the beach Dinghies & Cats

The use of Yardsticks allows off the beach dinghies and cats of different design and built to compete against each other in the same race.
The Yardstick is an Internationally defined and accepted adjustment factor for dinghies and small multihulls. It is in essence a percentage value. Its neutral value = 100.0 (%), where Elapsed time equals Yardstick corrected time.
The higher the Yardstick value the slower the boat.
The basic formula is :

An Elapsed time of 50 minutes for a Tornado (YS = 65.0) and for a Tasar (YS = 107.5) becomes : To enable Yardstick results to be calculated by Top Yacht in a Series :

• Select the Mixed Class YS module on page 3 of the Series SU Wizard Form

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Personal Handicaps
Whereas the Yardstick reflects the capability of the boat, the Personal Handicap reflects the performance of the Skipper and Crew.
The Personal Handicap is calculated by dividing the YS Corrected Time of the Reference boat in the race by the YS Corrected Time of the Competitor.

On the Top Yacht Results page the Reference boat used for handicap calculations is highlighted with a bright green background.

Where there are no previous Personal Handicap data available an Initial Handicap default value of 1.000 is entered by Top Yacht. The Handicap gradually develops from there.

To enable Personal Handicaps results to be calculated by Top Yacht in a Series :

• Select the Mixed Class HC module on page 3 of the Series SU Wizard Form

HC3. Keelboats & Trailables

The use of Australian Measurement System (AMS) adjustment values allows keelboats and trailables of different design and built to compete against each other in the same race.

The AMS values perform therefore exactly the same function for the keelboats and trailables as the Yardstick does for dinghies and cats. However there is an essential difference in nature between these two types of values.

• Whereas the Yardstick operates as a percentage factor by which the various Elapsed Times are divided
  
  
• the AMS operates as a handicap factor by which the various Elapsed Times are multiplied

The higher the Yardstick value the slower the boat.

The higher the AMS value the faster the boat.

To enable AMS results to be calculated by Top Yacht in a Series :

• Select the AMS module on page 3 of the Series SU Wizard Form

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Performance Handicap
The Performance Handicap is calculated by dividing the AMS Corrected Time of the Reference boat by the Elapsed Time of the Competitor.

Note that this is markedly different from the Personal Handicap calculation of the dinghies where the YS Corrected Time of the Reference boat is divided by the YS Corrected Time (not the Elapsed Time) of the Competitor.

The Performance Handicap combines in a single value the boat's design and built element and the skill of Skipper and Crew.
This value is therefore a reflection of the overall performance, but it hides the contribution value of each of the two components. A sluggish boat with an outstanding crew for example, can have the same Performance Handicap as a faster boat with a mediocre crew.

Where there are no previous Performance Handicap data available an Initial Handicap input value = AMS is usually applied (manually). The Handicap gradually develops from there.

To enable Performance Handicap results to be calculated by Top Yacht in a Series :

• Select the Keel TOT HC module on page 3 of the Series SU Wizard Form

HC4. 'Yardsticks' for Keelboats & Trailables

Because of their different nature AMS values for keelboats and Yardsticks for dinghies can not be compared directly. However a direct comparison is possible through a simple calculation : inversion of the AMS value.

These calculated Yardstick values may have two practical uses.

1. Individual Pursuit races
It seems unlikely that the thus defined Keelboat Yardsticks fit perfectly into the International Yardstick table for dinghies and cats. However the values do not appear to be too far off the mark, at least for the prevailing sailing conditions in Darwin.
Most of the calculated Yardsticks for keelboats in the DSC fleet fall within the 110-130 range, which is just above the International Yardstick for Tasars (107.5).

With a little experience guided juggling (up or down) between the two Yardstick families a workable fit may produce a complete Yardstick list of the entire Club fleet. Such a list could be used for example to define a realistic starting sequence and start interval times for an individual pursuit race, like for example the DSC annual Patron's Trophy.

2. Personal Handicaps for Keelboats and Trailables
The Keelboat Yardsticks can also be used to calculate Personal Handicaps (reflecting the relative performances of skipper and crew only) for keelboats and trailables in the Top Yacht application.

To do this a new Yardstick must be created for every competing Keelboat and Trailable in the fleet. This is a simple task (TY Workshop Chapter 18) which requires very little time to complete.
Then to enable Personal Handicap results to be calculated by Top Yacht in a Series :

• Select the Mixed Class HC module on page 3 of the Series SU Wizard Form

Use the value = 1.000 as Initial Handicap for all Competitors. The Handicaps will gradually develop from there.

Comparing the results from Performance HC and the Mixed Class HC tables on the results page, show that the Handicap Corrected Times for both are almost identical. Which is as it should be. The minute discrepancies (of a only a few seconds) between the two are caused by the necessity to round the Yardstick value for each keelboat to one digits behind the decimal point only.

HC5. Top Yacht Calculation Values

For each type of Handicap (Personal or Performance) Top Yacht calculates three separate values.

1. Back calculated Handicaps (BHC)
   BHCs are calculated as described under Chapter 2 and Chapter 3 above, at the end of each race.
   
   
2. Calculated Handicaps (CHC)
   CHCs are generated each race by calculating the of the previous four BHCs for which a Competitor had a Finish time. The BHC must lie within a predefined range around the general Handicap trend line. The Top Yacht default for this range is 4% on either side of the trend line. For the DSC this range is currently set at 10%.
   
   
3. Allocated Handicaps (AHC)
   The AHC is the Calculated Handicap (CHC) for the last race the Competitor competed in with a recorded Finish Time.