I play 4-5-1V about 75% the last few seasons. I've noticed that since the 2017 update its been rather poor when playing against attacking formations with counters. Before If an equal or lesser team would play with say 2 AM and 2 ST i would chew them up with the counter. Now it just doesnt seem to work. I get ground down and their shot on goal ratio is about 50%. I maintain my team and watch almost every single game, so i know its definitely a change in the game's algorithm. I find that when I'm not getting it done with 4-5-1V I switch to 4-3-2-1 and sometimes i can swing things in my favour. Same tactics.