A good read:
A while back, I was puzzled why Jaime can "distribute" by simply leveling the portafilter w/ a scrape of the doser lid and get a beautiful pour. This was also the time I had a lot of problem of uneven pour out of the basket. It was then I found out that my grinder (in conjunction of the way I dose) causes the coffee to deposit more on one side of the basket. This results in differences in the density of the grinds (in the basket), and that the post leveling/distribution move (schomer/stochfletch/chicago chop) did not help to distribute the coffee (especially the lower-half) much at all. It was not until I start to pay real attention to de-clump and center the ground falling into the basket till I have some decent pours.
I think Alistair said the best:
"Distribution is a fix for coffee that has been dosed unevenly in the basket. Concentrate on the landing."
So forget all the focus on the different "distribution" moves and pay attention to the dosing that actually distribute the coffee. Fix the root cause, not the sympton.