Bernie Wojcicki was an Australian whip maker that made several thousand whips over his life time. Unfortunately I never got the chance to correspond with him as he died in 2016, a few months before I became interested in the craft. He did a series of videos over the last 10 years or so of his life and they are available on his YouTube channel, Bernie46
https://www.youtube.com/channel/UCnAT3qbpSM6YyN53PBOztBw
If you are at all interested in this art you should watch his videos.
This transition is buried in a video he made showing how to do a 16 plait diamond braid for the handle of a bullwhip and this is how he transitioned from the diamond plait to the herringbone plait for the thong.
This is the starting position-the next strand to be worked is the upper right-hand strand (silver.)
the silver strand is pulled around behind the piece and plaited U1, O1, U1,O1, U1, O3
This is repeated on the right hand side, bringing the uppermost left-hand strand behind and U1, O1, U1, O1, U1, O3
The nest upper right-hand strand is brought around behind and U1, O1, U1, O5 
and then repeated with the upper left hand strand
The next upper right-hand strand is brought around behind and then U1 O1, U2, O4
mirrored by the upper left-hand strand
Now the herringbone is established and you continue on with and under 4, over 4 pattern.
Palo Duro Whips 
I followed Bernie for years, I miss him.
This is just what I was looking for and couldn’t find in his videos.
Thanks so much!
LikeLike
You are welcome, I learned a lot from Bernie and feel obligated to pass it on.
LikeLike
I only started to learn more than 2 year ago. How can I recalculate this for an 18 plait whip?
LikeLike
Hello James. Here’s how I’d do it
ouououo3 on each side
ououo5 on each side
ou3o5 on each side
u4o5 on each side
Mark
LikeLike
Thank you my friend. I appreciate you. James
LikeLike
I’m afraid I made a mistake. Not thinking I though to more strands was an 18 plait. I added two more which is a 20 plait. Crap! Does it work the same way but rather starting Over I start Under?
James
LikeLike
Here’s a link to the transition in 20 plait. Open the menu and click on “Start braiding” and it will give the steps. It’s a great tool once you learn to use it. http://www.whipinfo.com/faceplait/?id=4212cebb275db4483412a75eef5b98bc
LikeLike
Thank you so much. It worked perfectly. I need to learn how one figured out ther strand placement.
LikeLike
Forgot about that tool. Thank you for the reminder. I’ll post how it goes.
James
LikeLike
Thank you by the way.
James
LikeLike
You are very welcome.
LikeLike
Me again. Been awhile since I last messaged you. Got a call for an 18 plait and remembered your formula. But I’m a little confused of how you wrote it. Please clarify.
James
ouououo3 on each side
ououo5 on each side
ou3o5 on each side
u4o5 on each side
I figured o3 u3 o3
o5 u4
u3 o5
u4 o5
LikeLike
Hi James, I’ve been using
http://www.whipinfo.com/faceplait/
to work out pattern changes.
Mark.
LikeLike