Why didn't my team make the playoffs? How were tiebreakers applied to my team?

If you go to the playoff bracket (League » Playoffs), there is a detailed breakdown of the tiebreakers in the left-hand column of the page (desktop view). If you don't see anything listed in the Tiebreakers column, then it means that the commissioner has edited the playoff seedings and the tiebreakers no longer apply.

Note: If there is a tie with 3 or more teams, the best head-to-head record can only be applied if one team has defeated each of the others or if one team has lost to each of the others or else it's skipped and the next tiebreaker option is used to break the big tie into a smaller one or to break the tie.