From Ptil Tekhelet:
This method defines a chulyah as between 7 and 13 twists. There are five (double) knots, with chulyot between them of twists that alternate between Tekhelet and white. The first and last twist of each chulyah is white.
Additional comments:
This is a method open to a lot of interpretation since Raavad holds 7-13 to refer to winds and not Chulyos. The second Chulya is practically non-important: it allows for all winds to be white for 7-8-11-13, it also allows for more than 13 winds in the event one needs to get a good 1/3rd-2/3rds ratio.
The second Chulya in this case ends with Techeiles, as 8 is an even number, it’s not physically possible begin and end with white with alternating Techeiles winds.Again, the only Chulyos that matter based on the Raavad really are the first one and last two.
The reason this is Raavad Style is because the knots in between are double knots. The Mordechai is big into the double knots and it’s convenient, even though double knots don’t “hold” nearly as well as Yemenite knots of the Raavad slip knot. It’s moreso a nod to tradition than anything else.
