There are no shortage of playoff fantasy football leagues out there. I don't do as many as I do in the regular season, but I do more different kinds of leagues. Here are the three I've been doing for going on 5-10 years now.
A disclaimer: these are just the ones I've done, enjoyed, and stuck with. There are many other (and perhaps better) ones, but these are at least a few of the most popular formats. I don't know if any of them are or aren't advertisers with us; one might be. But that wasn't a factor in my naming them, apart from maybe that's how it first came to my attention.
RealTime Fantasy Sports Playoff Challenge: This one I've been doing for a while and have had some success with it (probably why I keep doing it). You can play in 10-team leagues that cost $20, $50 or more to enter, with prize money for 1st and 2nd place in each league.
Each team picks a 14-player roster for the entire postseason, and rosters lock once the first playoff game kicks off -- no adds or drops from that point forward. Eight-player lineups (QB, PK, D/ST and 2 RBs, 2 WR/TEs, and a flex spot. Strategy involves a balance of the best performers each week and the players from the teams who play the most games (which could involve a non-Super Bowl team, since Ravens and 49ers are off this week). All different strategies are fair game; sometimes teams will go light in the opening round, but be more certain to have full lineups for the Super Bowl (if the top seeds both make it). Other teams will believe some wild-card team is going to make a deep playoff run and load up on Dolphins or Packers, blowing away the field if and when that team makes a Super Bowl run.
I've gone different ways, but my lean this year is to have 3 QBs from the teams I think are most likely to make it, 5 RBs, 5 WRs and probably a kicker. Defensive scoring doesn't seem high enough to invest in such a team, and I have to be sure such and such team is going to the Super Bowl. I'm still working out my roster, but I'm glad to share it later this week. My early thought is to go NFC heavy, since the top 2 teams in the AFC (Ravens and Bills) both play at venues that might be affected by foul weather. Cowboys, Lions, Rams, Bucs will not be; Packers and Eagles might lose this week. Jared Goff or Matthew Stafford playing two games in a dome (if that happens) might be better than Josh Allen playing three games outdoors. Might.
FFPC Playoff Challenge: I play this one, but I can't say I've ever done particularly well. It has $35 and $200 entry levels (I do the cheaper one), and you're competing against thousands, hoping you can chance upon one of the better lineups. In this one, you're filling a 12-player lineup (QB, TE, PK, D/ST, 2 RB, 2WR, 4 RB/WR/TE Flex spots), and your choices lock once the playoffs start -- no moves at all. You are allowed only one player from each team. As a result, you need to decide whether you're better off with Brock Purdy and CeeDee Lamb or Dak Prescott and George Kittle -- who will play more games, and who will score the most in them. I think you get double points in the Super Bowl week, although don't quote me on that.
Naturally, you will lose at least 4 players this weekend (some will lose 5 or 6 and be essentially out of the running), and 4 more in the Divisional Round. Ideally the ones you lose earliest will be the lowest scorers (a kicker and defense, perhaps), while the ones who advance and play the most games for you are the highest scorers. You also need to weigh whether it's good to zig while others zag; if everyone has CeeDee Lamb, am I better off with a lesser name (say if Dallas gets upset in its first or second game). Will Deebo be better than Aiyuk? That kind of thing. (This by the way is moot, I can’t imagine using any 49er instead of McCaffrey.)
My problem with this game (and a lot of big competitions) is that I know some people are doing multiple entries (5 or 10 or 20), dramatically increasing their odds of winning, and I just don't like spending that kind of money. Am I just throwing away my entry fee if I only do one entry, and hope none of my key guys get upset? But that's why I do the $35 one; what the heck. I enjoy the challenge, but I also feel like the odds are stacked against single-entry players. As I said, I haven't excelled at this game. I think I had one good year (but I do better in the regular-season FFPC competitions).
OfficeFootballPool.com: This one I've been doing for a few years with an ever increasing group of friends/family members/co-workers. There are numerous variations on this league available around the Internet. In it, you pick a starting lineup each week during the postseason, but can only use each player once. So the trick is to pick top performers from teams you think will lose (so you'll have more options in ensuing weeks). If I picked a lot of Cowboys and Steelers this week, and those teams advance to the Super Bowl, I may as well just throw my money in the street.
For this one, I'm looking at NFC teams this week, since I think that's where the highest scoring games will be, and that's where weather is less of a factor. If I go that route (loading up on Rams and Lions for example) I'll probably favor the NFC the next two weeks as well, so I'd have all players available from whatever AFC team makes it to the Super Bowl. The risk comes if I happen to use a lot of Rams and Packers this week, and both underdogs win, and I'm basically down to only 2 available NFC teams (San Francisco and whoever wins the Bucs-Eagles game) for the rest of the playoffs.
This particular game I have done well in, and the Weekly rankings are helpful (as is our Playoff ReDrafter). Finding high-scoring players from teams that lose each week (spoiler, I'm probably using Tyreek Hill this weekend) feels like an easier strategy avenue than from either of the other competitions, where you'd better hope there isn't a key upset or two you didn't see coming.
Those are the ones I play. Please feel free to discuss your own such favorite playoff fantasy leagues below; I know there are others. Later in the week, and in my Saturday preview column, I'll talk more about the rosters and lineups I went with.