That is terrific information, Mary. Thank you.
Very interesting to compare one side of the lane to the other. Because there are fewer lefties and a fair proportion of them play in similar territory, their side remains comparatively static. Whereas the RHS cops more traffic, which removes more oil, creates more breakdown and the subsequent the need to migrate further in, necessitating a higher rev rate and maybe even stronger ball to create angle and carry, thus removing more oil... You get the picture. It's a bit of a vicious cycle.
As Andrew said, easy to see just how destructive the balls are to the pattern. Imagine what they do to your typical 10:1 house ditch, where almost no oil is placed outside. All that friction is exposed to unprotected lane surface, destroying it over time. And that time gets shorter as the balls get stronger, accelerating our collision course with panel death.
Thanks again Mary. Good stuff.