There was an interesting article on Tompkins site (not written by him) that stated we still use the "gegnpress" just as much, but in different area's, which has led to a misconception that we've abandoned it, rather than just modified it.
The stats and evidence were certainly impressive, and did lend weight to the argument, but I'm not 100% convinced that we press as much.
As I said previously, I don't really see 2 different systems, I see many variations on the same basic principle of Klopp's 433, attempting to use space effectively and create overloads in certain area's where (I assume) a weakness has been identified.
I don't see a 4231, because that is a rigid system, which does indeed employ a true "double pivot" of a holder/destroyer and a playmaker, which basically breaks down into a 6-4 ratio, rather, I'll go back to my "staggered 3" and the variations employed within the fluidity that it provides.
You've given me a few things to think about which is the whole point of the forum
It's more a shift towards control in some conditions.
If we viewed "Heavy Metal Football" as almost chaotic in it's appearance,
we have definitely seen more definite controlled play in games where Klopp & the team have looked to grind out a result,
nearly wear them down, before seeing the intensity ramp up.
Subtle but important changes.