In July we will look at rating systems. This week we will look at Americap which will determine the winner of the Chicago Mac race. Next we’ll look at PHRF which is widely used, then box rules and finally one designs.

The Americap II rating system will determine the mono hull handicap winners in this years Chicago Mac Race.

Americap II is a rating system combining multiple elements. Included are boat measurement (similar to IOR), Wind velocity and direction (familiar from IMS) and a combined time on time/time on distance scoring (both methods used
in PHRF). Unlike PHRF there is are no subjective components that maybe
finessed by boat owners.

For those racing, or spectating results are figured a little different with Americap II. A 2 part equation is used, infolding multiplication and subtraction.

The equation is as follows: CT= (A * ET) - (B * Distance)

Corrected time= Corrected Time


ET= Elapsed Time in seconds


Distance= Distance


A= Time on Time Co-efficient (seconds per mile)


B= Time on Distance Co-efficient (seconds/second)

The scratch boat has an A coefficient of 1 and a B coefficient of 0.

The ratings displayed on the Chicago to Mackina official scratch sheets at http://www.chicagoyachtclub.org/racetomackinac/ScratchSheets/index.htm are the 10 knot rating.

Last year was the 1st time that the Mac race used Americap II. A look at the winners list shows that at the very least Americap can’t be said to have a bias towards older boats, as several oldies but goodies were overall winners.

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