Most fantasy football regular season schedules are about 13 weeks long — give or take a week based on number of playoff teams.
As a guide, I always say that by the ninth week in the season, you should have a good idea if you’re headed for the playoffs or not. This is not always the case — I participated in a league in 2015 where eight out of the ten teams in the league were .500 after 10 weeks.
But as a general rule, you should know if you are able to make a playoff push or not with four games to go.
At this point in the season, you need to cut off trades so that you don’t have owners who are tanking the rest of the season give up talent to a playoff team for nothing. You want to maintain the integrity of the league from start to finish and cutting off trades helps ensure that owners are not padding other teams’ rosters.