...and don't give me grief about the middle finger...
I'm series (child, don't follow FReeper spelling!!!)
...if the index finger is on top of the fist...the thumbs go the other way!!!
..follow the pattern of the right and left index fingers and try it.
DING! DING! DING! We have a winner!
You're right. I just tried it. It depends on which index finger is on top. Whichever index finger is on top, that's the thumb on top (which makes sense because otherwise the fingers wouldnt't be properly interlaced. Two fingers from the same hand would be next to each other).
But even with that, there's definitely a way that feels more "natural" to me. I'm a righty and left index finger/left thumb on top feels the most natural. But if, for some reason, I put the right index finger on top then right thumb on top would follow.