[BobS]

I have the solution. The thumb on top is not determined by thumbs- it's determined by the position of the index finger. It's apparently a random effect. The right thumb will be above the left thumb when the right index is above the left, and reverse. There is the azimuth, elevation and range angles of approach between your hands that determine where they are comfortable together.

I tried this 20 times with my eyes closed both in front and behind my back. Your more powerful side will lead the weaker side in whatever arrangement is appropriate in that instant.

Don't discount the elbow and shoulder rotation and the fact there are 10 things in opposing force coming together. That makes it random.

Bob!

[Happygal]

Oy vey! Ye is talking all physics to me.

You DO know I'm blonde, right? *L*

[admiralsn]

OK, your splanation sounds waaaaaay better.

[paulat]

Thanks, saquin

the rest...see post 206