Downhill slope

I'm pretty new to top eleven and I've been seeing a lot of your posts and guides around (very useful by the way). I'm in my first league at the moment, using the 4-5-1v formation. I changed to this formation about halfway through the season and had some very good results with it.

I am still top, but now only two points clear. Now though I'm losing or drawing most of my games, yesterday I lost to the second worst in the league. All my players have good form, good condition, good morale, and are in their preferred positions. I don't know what to do, and the guys behind me in the league are catching up. What do you think I'm doing wrong?
If you need any screenshots or further information please just let me know :)

Thanks in advance

Perhaps he played a counter formation to yours. Or had better orders/tactics, which you cannot really see except live.

I would check out the counter formations thread, and examine the losses to see if that was it. There's as well the random factor to the game.