So... first loose in my new season. I am lvl3 14.7 stars losing to a 11.3 stars lvl4 ... And i took TDs against a RB 7 stars (12 speed, 15 attack acceleration) and KR 8stars with bad stats... against my LB and S with 25 in speed, stamina, tackle, anti-juke, defense acc... My rythm is at 50% att and def speed at 50%. All players at 100% rest.
And what is incredible, is that RB is just too fast to only can be touch... I thought, "wow it must be a 40stars RB that i can not stop now"...
I do believe LVL of team change everything !

Plus the fact, i've played another match against a team where OL was K/WR, S were QB, LB were WR... and the team overall was 18 stars lvl8 then i lost... looks like assignements don't care in the game, only players lvl.

Total nonsense, to me, and IMO it is killing the game... at least my interest...

Unfortunately I cannot agree with that statement, I've been beating under developed or poorly developed teams of much higher levels quite consistantly and even some teams who have been developed correctly with strategies that I managed to figure out. I made the top 20 rankings with a level 10 team vs what was then level 14's and there are players of the same or lower levels that did even better than that. I'm not saying level has no influence, as the 5 stat point cap per level does make a difference, but if the stats aren't maxed to the cap it doesn't suddenly make your players better. The guys that are in higher levels had to do something right (strategy wise) to get there.

From what you've said regarding your rhythm and speed settings it is very likely that the opponents you have faced have set their settings much higher than yours. Changing one thing can influence another so you still need to find that sweet spot and the only way of doing that is losing and learning from those losses.

And this has been highlited many times in the past, do not be fooled by star rating, and dont just look at eg speed, stamina on attacking players, there's multiple stats that will influence how players react.

First things first: the only thing a level changes is the cap on max stats. Level 3 cap is 50. level 4 is 55. Star rating is also very misleading- my rating is high 20s, but my starters average to upper 30s (and their position relevant stats are always pushing my level's cap).

Second thing to point out: your speed is at 50%? Bad idea, even if you have 50 stamina (which I doubt, since you've said you're at 25 in obvious LB relevant stats despite being level 3). I routinely beat opponents with similar stats and higher speeds because their guys wear out. At your level, I kept my speed set around 15%-25% and used a custom formation to compensate. That's probably why you're giving up scores- your guys play great at first, but probably within a half (less if your stamina is low) their stats are cut in half or worse because they're tired (which is something we tried to explain before).

As for position assignments, what matters is the stats. If that OL has good carry, speed, and anti-juke/penetration, they will beat your defenders. It's no different than Mike Vrabel catching TDs for the Pats even though he was an LB.

I think that he might have lost to MB (Match Bonus)

Thank you all for your support! I've found my solution (special thanks to Ryan Derenbecker). I've just put my Rythm to 70% (instead of 50%) and all my players run faster (as fast as my opponents) and they don't get tired that much. So i scored 3 or 4 TD, and i've made a lot of interceptions or 3 and out...
I can now concentrate on stratégies and attack/defense speed sliders.

Thank you all again for your time !

Be careful, because that comes with a drawback as well. Rhythm makes it harder to tackle/dodge, so anyone with solid tackling/tackle breaking stats will be a tough matchup.

Add to that the biggest problem in lower levels....Injuries.

70% Rhythm is at the peak I would go. My best results are around 65% defensive rhythm. But nothing beats decent training regiment.