Actually the Texel system does not contain much formulae.

Actually I found when researching updating it that I could approximate it extremely well by three linear dependencies. It may look complicated to some but the real Texel system behaves very much just like :

Rating number : 148.92 - 2.75 * rated sailarea - 6.141 * rated length + 0.132 * rated weight

A summation of just a constant and three weighted variables.

See the picture below for the dependencies :

Texel higher order formula are in pink
The linear approximations are in blue

All graphs have been scaled to have the lines start or end at 0. So the numbers on the vertical axis are differences in ratings relative to a given constant and not actual ratings. But this is not important when looking at the shape of the dependencies. Also all constants are later combined into the 148.92 constant given above.




The blue lines are straight and the pink lines are every so slightly curved. However it will be clear that the curves are so small that it hardly matters.


So in fact calculating a very close approximation of Texel can be as easy as performing 3 multiplications followed by four additions. Not much higher math here. If you to get that extra 1 % accuracy than you'll have to perform 3 addition calculations (rise to the power ...) . All in all MUCH LESS math than involved in regressing race data to PN numbers.

Wouter