I joined halfway through my first season so only managed 4th, during that season I tinkered with formations and got mixed results, buy the end of the season I had one formation that seemed to do best against every other formation. I use 3-1-4-2...DL, DC,DR,DMC, ML,MC,MC,MR,ST.ST, I always have two of each position this helps for a few reasons, 1 cover for injuries, 2 I play the identical formation in the cups with my spare players, 3, if on occasions im losing a match I take off my DMC and put on a 3rd striker, or if im playing an opponent with a far better skill level I revert back to a 4-4-2 formation dropping the DMC for another DC. I also usually keep one AMC for emergency purposes so in the cups I can ofton play a 3-1-4-1-1 formation if I lose to many ST to injuries or suspensions. this works really well for me, I have won 4 league titles in a row since and am 9 points clear with two games to go this season so this season is rapt up as swell!, I have not won any cups but have not ever tried to, I never play my best 11 in the cups as I save them for the league which is why I do really well in it, the main reason for this is it is very hard to keep all players near/fully fit playing your strongest team in all 3, as soon as players get injured,suspended you run out of cover and as the players are really tired there league form drops, unless you are prepared to chuck lots of money at it on booster packs which I DONT, then my way is excellent. one final thing to take into account, the league is worth a lot more in winnings than the cups so it makes sense to me to prioritize the league first, if like me you wish to do that just try and get to the group stages of the CPL so you get a little bit extra revenue.