SSD write leveling?

I don't understand his math.

First off, the limitation of number of writes is for a block. Not for a specific byte in a
block. Thus the worst load for a flash is not a sequesial logger. It is an application that
wries 1 then 0 and then 1 again to the same byte and does this to random bytes all over.

He later writes an explanation as to why that data recorder "does the fastest damage". But I
fail to folow the reasoning there.