Do not use logic when it comes to discussions about ratings

Ok, so not many production boats would have a spinnaker pole that is 5 feet over J, but sure what the hell...

If a production boat A comes with a regular spinnaker pole and boat B wants to convert to a bow pole and Asym, they would receive a 6 point credit for the change from articulating pole to non articulating bow pole.

(The powers at be decided that loss of an articulating pole would slow the boat down, equal to a 6 points.

The old PHRF BC rule had an additional penalty, in that you would get hit 3 secs for every foot of bow pole that you added to J plus 1 foot. (The first foot was free) So if you add a 3 foot bow pole you would take a 6 point hit. (Not sure how 3 foot of bow pole is as quick as a articulating pole down wind, but there you have it)

The New rules have switched to a JC x 1.8 rule, in which the bow pole can be as long as you like, but the calculation of sail area will take that pole length in to account. So if your JC is 15 feet, your asym would need to have a mid girth of 27 feet or greater. ( Any girth smaller than this would be the same rating hit, as the bow pole would hold that mid girth at JCX1.8, or in this case 27 feet.

Then it just comes down to sail area, efficiency of projected area, efficiency of the sectional shape of the sail and the boats weight. Asyms really only start working like a foil at angles smaller than 130* AWA, there is some stalled out angles that can work at higher wind speeds, but for argument sakes, 130* is about as low as an Aysm can sail before it gives up too much VS the same sail area in a sym spinnaker. (Assuming square courses) See attached polar chart.

So under current PHRF BC rules, the bow pole its self does not penalize you more than a Symmetrical sail of the same size, but due to the limits of the fix on center line bow pole the AWA limits of an Asym, will all really hurt heavier boats with Asymmetrical sails more. (limited boat speed potential - can not dig down wind to save distance sailed)