Simply put....

SCHRS provids a rating based on the boat, sail area, length, width, crew number, number of trapeses, daggers or not etc.

PY (US or UK) provides a rating based on the performance of the boat and the sailors who sail it.

consider a really difficult boat to sail. It will have one SCHRS rating.

Every year, as people get better at sailing it, the PY rating will change; this reflects the ability of the people sailing the boat, to sail the boat at it's petential.

Consider an old boat that is not sailed much. It will have one SCHRS rating, the PY tating will slowly get easier (slower) as less people sail it and so less people win stuff (the good guys usually sail in big fleets where the competition is).

So, after a while, the PY rating will become "easy" making the boat a bit of a bandit and as soon as a decent sailor "borrows" one, they clean up as the PY does not reflect the speed of the boat, it reflets the speed of the boat, and ALSO the speed of the people who sail the boat.


PY also does not allow rapid developemnt of classes as returns (Results) need to be gathered to create a rating.

SCHRS (or TEXEL), you just plug the data points into the rating engine and a rating pops out.

Due to a lack of PY data for cats. Original UK conversions used the original classic tornado rating (1.00), took its PY rating (691 I think at the time) and used the SCHRS difference to give a PY to use for the cats. Not ideal I know but some clubs were happy using it. Now I think they use the F18 as the datum point for calculation purposes. You can calculate the same using your US portsmouth rating for the F18 as datum.

Cheshirecatman

True but only because of the way the PN rating is being implemented!

The solution is to make a new rule for this circumstance consistent with the basic PN assumptions.... eg the boat is actively raced in its class.

so... I propose... when a class does not hold a nationals with 10 boats for two years. the PN rating is frozen at the rating when the class last managed a nationals.

There is a fiddle factor to convert SCHRS to PY of "multiply SCHRS by 686"; BUT remember you are not rating like with like.

PY rates the sailor too; I would thus suggest (as the RYA do) that you then convert the resultant PY to something meaningfull for your club and conditions.

Over here, we used the PY numbers from the 2 largest classes, the Hurricane 5.9 (691) and the Dart 18 (798) to get a good balance when we needed to convert other classes from SCHRS to PY.