The revival of 4-4-2 as a viable formation started back in the early 2010's and Bayern Munich adopting a version with Mario Mandzukic as the main target man and Thomas Müller drifting off of him. They managed to beat Barcelona 7-0 over two legs. Athletic Bilbao also despatched Barcelona playing it.
Arrigo Sacchi pioneered this modern day 4-4-2, with his AC Milan team from 1989 to 1991, with the team as a whole compact in defence, harmonised in such a way as to restrict space and make play predictable onto one side of the field.The entire team was expected to defend and to attack. Baresi, Costacurta, Tasotti and Maldini were encouraged to be the originators of attacks, from wherever they won the ball, as were the other players within his system. Rijkaard and Ancelotti would always be available, moving without the ball to supplant the attacks and to augment zones in defence. The concepts of third player running, whereby one player passed the ball into the feet of a teammate,who played to the second, for the first man to make a run beyond the second player and receive into space and underlapping runs of full backs, getting on the inside of a winger to receive the ball and advance forwards stemmed from here.
It always makes me laugh when a pundit lazily throws out zonal marking as an excuse - this team was the epitome of defending zones, try scoring against them!
Ancelotti took that 4-4-2 back to Milan, with Pirlo, Seedorf, Kaka and Gattuso. Diego Simeone repeats the feat today with his variation on Sacchi's model. Paradoxically, using the wide areas to press and the central area of the field to contain and then flooding forwards quickly.
The main reason 4-4-2 has had a rebirth is due to teams insisting on a slow build up from the back, a defensive midfield duo and the concept of latency and low risk formations such such as the 4-2-3-1. Players can see the passing lanes much more clearly, support play is built into it naturally and it offers a wide number of options when it comes to cycling the ball, movement off of it and defending is easier, you simply outnumber the opposition, or drop deep and pack out the field. With 4-4-2, especially as Sacchi/Simeone/Ranieri/Ancelotti have it, players must work. Hard. Players must be ready to sacrifice and there's no hiding places.
Some may say that 4-4-2 is not effective any more. My point is this - systems of play are still only as good as the players playing in it, their preparation and their understanding. Sarri, Mourinho, Guardiola have all used a bastardised 4-4-2; at Napoli, Inter and Bayern respectively.
The more things change, the more they stay the same; soon we might see a team break out the W-M formation.
The way I see it, we have played the 4-4-1-1 variation of the 4-4-2, Powell as the deep lying forward. For some reason, Cook has pushed the wide players back, but what I find puzzling is that the full backs aren't going beyond these deeper widemen as much, nor are the wide players coming inside to squeeze the opposition. I'd like Cook to revert to the 4-2-3-1 that the players are comfortable with and for the more positive, forward thinking approach to return.