I know there is a Glossary entry for this, and I've read a couple other things I'm not understanding, either.

Can somebody explain, in plain English, what the "positive axis point" is?

Thanks in advance!

It's the initial axis point on the side of the ball you see when it's rolling down the lane.

That means that when the ball initially hits the lane, if you drew a line through the ball so that it looked like the ball was revolving around that line, it would be the spot on the ball that you can see where the line came through.

As the ball flares, that axis point migrates to different locations.

put a piece of tape on the side of the ball you see when you throw it.position the tape so it spins in the tightest/smallest circle possible so that it looks like you have a big dot on the side of your ball when you throw it.thats your positive axis point.