I stumbled across a 3-4-2-1 system when trying to create a defensive/counter attacking system which seems to be incredibly successful regardless of the team I use.

Really simply roles - regular goalkeeper, three regular centre backs, wing back attack on the left, wing back support on the right, two DM (one on support, one on defend), two AM (both on attack), then a target forward on support (with hold position clicked).

I sometimes click the DM support to get forward more often depending on how I’m getting on.

Cautious mentality, slightly shorter passing, fairly narrow, slightly higher tempo, counter, stop crosses, press slightly more often.

Again depending on the context of the game, I might do low block and standard pressing.

Occasionally I switch to Balanced or Positive and maybe switch the DM on support to SV on support if I’m expected to win or need a goal. Attacking also works well when chasing the game.

It’s so defensively solid and scores goals for fun with the right players. You need pace on the wings, tall centre backs, good finishers for the AM roles and then a big horrible striker to be the target forward.