Seeded, with every game numbered. 22 games plus 1 if necessary. Free PDF, no ads, no sign-up.
With 12 teams, seeds 1-4 get a bye and skip the first round. Seeds 5-12 play 4 opening games, and the winners move on to face the top seeds.
It's double elimination: a team is out after its second loss. Seeds 1 and 2 start on opposite halves of the winners' bracket. Teams that lose in the winners' bracket drop into the losers' bracket ("Loser of 3" means the team that lost game 3 plays there next). Every team is guaranteed at least two games.
There are 22 games, plus one more if necessary: if the losers' bracket team wins the final, both teams have one loss and they play once more for the title.
Game numbers match SportsGrove's brackets and the common printable sheets, so a printed copy lines up with a bracket you run online.