Dunno really.@Liu Kang what you think about the back 3 becoming more and more popular in the PL? Think I saw Hull play with it recently stopgap measure for injuries or an emerging trend?
@mastermind
May have to do with the lack of old school crossing wingers because now they all drifting towards the goal so full backs seems unnecessary then as they provide width in the back. Fortifying the axis seem to be the best solution against them because instead of having two CB, you got 3 though there is then space behind the one person on the wing. There was also this trend in 4/3/3s with the 6 dropping low between the CB allowing the FBs to push higher and making it de facto a back 3 or a 2+1 in attacking phase. But it also depends on how many forwards the opp has too : usually back 3 is a good solution against a front 2 but it seems overkill if there is only one. Maybe it's also because of false 9s dropping letting the finishing to the (2) wingers (à la Real Madrid for example) or with teams with very attacking midfielders seconding a lone forward. Ultimately, trends come and go.
But it's weird because the back 3 was revived in the Serie A with Juve, Napoli and/or Inter a couple years ago and now those teams are slowly avoiding that type of defense. Benitez came back to a back 4, same as Mancini for Napoli and Inter. And Juve struggles with the back 3 in the CL and sometimes they revert back to a back 4 though they ain't really successful either.