any formation with 4 defenders as you need fullbacks to defend their wing attacks. I don't know why ppl say 4-5-1 V is efficient against 4-4-2 because to me it's the other way around. To attack 4-4-2 successfully an AMC roaming in the hole is very effective. 4-3-1-2/4-2-3-1/4-3-2-1 are all effective if you know how to take advantage of the space between their defense and midfield. If you are superior I would even go 3N-4-1-2.