The gegenpress (counter press) is a strategy to regain possession immediately after losing the ball with in 5 to 8 seconds.
Winning the ball back immediately after losing possession opens up the possibility of a counter attack that has been forced by the team applying high pressure. In such a scenario the team losing the ball has lost possession whilst they were transitioning play and have hence players out of position. Which allows the high pressing/counter pressing team to breach the back line of the team that was sitting in a low block without the ball and hence create a goal scoring opportunity.
To add to this. The goal is also to score within 10 seconds of getting the ball. Which means attacking with high pace, quick tempo and movement and quick forward passes - rarely passing backwards or sideways, unless that unlocks a run further up field. Possession is not an inherent goal of this style.
Sancho, Rashford and Greenwood should all thrive in this system, provided they learn to press effectively. I reckon Fred will be key early on - which I never thought I'd ever say, but there we have it.
A front three of Rashford, Greenwood and Sancho, backed up by Bruno, Van de Beek/McT and Fred, with AWB, Varane, Bailly and Telles/Shaw. Is what I reckon we'll start to see. Maybe one of the youngsters could get involved. I reckon we go for a box to box midfielder in January to partner Fred, or an eminent ballwinner like Bissouma, Rice and Ndidi. Maguire is probably done, and Ronaldo will likely be a regular sub-on option - unless of course he is even more godlike than we think, which is a distinct possibility. Pogba is as good as gone unless something changes, his long range passing could be a great weapon and the quicker passing style might actually suit him more, but he'll have to do some mighty impressive running to be involved. Who knows, maybe he'll actually come good.
I am surprised we aren't further behind than we are, and with some very winnable games coming up I think we'll gain a few positions by Christmas. It will be interesting to see how this all unfolds - but I think the real magic will be apparent in the next couple of years to come.