In Competition A, a full season of MLS play weeds the MLS teams down into a group of 8, which advance into a single-elimination tournament that decides a final champion.
In Competition B, a full season of MLS play plus a qualifying tournament weeds the MLS teams (minus Toronto) down into a group of 8, which advance into a single-elimination tournament along with a host of lower division teams which decides a final champion.
Is there any substantive difference between the two? The latter tournament doesn't include Canadian teams (of which there's currently one) but does involve lower division teams in the final bracket. Other than that, they're the same, and frankly based on those descriptions Competition B sounds the most interesting and prestigious.
Competition A is, of course, the MLS playoffs and Competition B is the US Open Cup. The MLS Cup final last year drew 46,000 fans (thanks in large part to Sounders Nation, naturally) and was broadcast on ESPN and Galavision. The US Open Cup final drew 17,000 — actually a banner number in a competition that regularly draws less than 10,000 for the final — and was broadcast on Fox Soccer Channel.
Soccer commentators in this country frequently kvetch that it's up to the teams to make the US Open Cup more important, or it's up to the marketers to make it more important, or it's up to the broadcasters to make it more important.
The fans decide how important it is. As you can tell from the record attendance that's going to show up at this final and the wall to wall coverage at Sounder at Heart, we're deciding it's important. No doubt spiteful fans of other clubs will swing by and try to minimize our accomplishments (especially if we win). "Ha ha, it's only the Open Cup, " they'll sneer. But they're wrong. Look at the descriptions of the competitions at the top of this article again. There's no rational reason to discount the importance of the US Open Cup. Most US soccer fans have just decided to, to their own discredit and to the discredit of soccer in this country.
Well, we're deciding it's important. It's a competition against every professional soccer club in this country and we won it and we're going to win it again. Preferably this year. But if not, we're going to be back. And if every other MLS fan wants to make a sour-grape face and act like the tournament is a joke because they didn't make it, that's their loss. They can keep whining about it while our trophy case fills up.