There are many threads about tanking and draw manipulation in the forum.
Basically tanking is to deliberately finish 8th or below to avoid level up and losing 20% squad skills by losing games whilst power training your team. Do that for a couple of seasons and you have a 140%+ team.

Draw manipulation means to sell your best players at the end of the season and keep 14 low quality so as to end up in a league, CL and Cup of similar quality teams then hammer the transfer market when the new season starts to make your team much higher quality.