re: Which sport has the best playoff system?

MLB would be the answer except for one problem... they change the number of games played in a week for the postseason compared to the regular season. This means a staff with two outstanding pitchers (or even one capable of pitching three times in a seven game series) has a much more profound advantage in the postseason than they do in the regular season.

For that reason I think the NHL and NBA have better playoff systems even though they both allow too many low seeds to make the playoffs. The NFL's one and done format (with too many playoff teams) combined with the enforced parity in the league has obviously been a mixed blessing. It allows most teams to be competitive and makes for an exciting system but results in a lot of upset wins by lower seeds who really shouldn't be in contention for the championship after the regular season.

College football actually might end up with a better playoff system than the NFL if their playoff amounts to a tournament of champions from the different conferences. There's a logic in that system and the absence of wildcards would be more likely to enhance the regular season than the NFL's system has shown to.