Even by the standards of European football it was impressive. Before kick-off there was a fan march through the city streets, most of it conducted under a billowing cloud of smoke produced by hand-held flares. Then, in the ground, a huge "tifo" was unveiled. Draped across one end of the stadium, it was three weeks in the making, covered 37,000sq ft, and required 70 gallons of paint. Finally 67,000 supporters, the third biggest football crowd in the world last weekend, prepared to savour a local derby.
"Local" is relative. The journey from Portland to Seattle is 173 miles, but in American sports that is local. Yes, this was Major League Soccer, the third-rate league David Beckham retired to. Playing standards still leave something to be desired, but there was nothing third-rate about the atmosphere at Seattle's CenturyLink Field. Clint Dempsey, MLS's new marquee signing, and one of the Sounders players depicted in the tifo carrying a flaming torch on horseback, figured in Seattle's 1-0 win over Portland Timbers. Afterwards he observed it was a far larger crowd than the ones he played in front of at Fulham and Tottenham.
The Sounders are the success story of MLS, a league which is beginning to think of running after years of walking, then gently jogging. MLS has deliberately expanded slowly, wary of the precedent set by the North American Soccer League (NASL), a star-heavy competition that boomed in the 1970s when such luminaries as Pele, Franz Beckenbauer, Johan Cruyff, Bobby Moore and George Best were drawn Stateside, and the New York Cosmos was the sexiest football team on the planet.
Boom was followed by bust and professional football flourished more indoors than out until, as part of the deal to host the 1994 World Cup, US authorities tried again. MLS began in 1996 with 10 teams and will be up to 20 when Manchester City's New York City FC franchise opens in 2015. This is not many in such a huge country and there are obvious gaps – notably in the south-east.
This may be solved by Beckham's return. As part of the deal that took him to Los Angeles Galaxy, Beckham has an agreement to purchase a franchise slot for $25m (£16m), which looks very good value after Manchester City paid $100m (£64.5m) for the right to play in New York (New York Red Bulls are actually based across the Hudson in New Jersey), and the Colombus Crew franchise and stadium were sold this summer for $68m (£44m). The obvious location is Florida, though two previous attempts folded in 2002. There is some professional football in the Sunshine State. Fort Lauderdale Strikers, coached by former England international Ricky Hill, and Tampa Bay Rowdies play in a second-tier league along with the re-formed Cosmos. All three names, like the Sounders and Timbers, hark back to the NASL which, confusingly, is also the name adopted by their league. But there is value in a brand. NASL gates average less than 5,000 but this summer's Rowdies-Cosmos re-match attracted 12,000.
As with most US pro-sports leagues, MLS has no relegation, operates a salary cap and has revenue-sharing. There is leeway to bring in star names (like Beckham) but not much. At $160,000 (£105,000) the average salary is half that paid in the Championship, which is why those UK-based players who cross the Atlantic are few and far between, and normally at the end of their careers.
Robbie Keane continues to prosper at Los Angeles Galaxy while Thierry Henry and Tim Cahill play for New York Red Bulls – as do the less celebrated ex-Charlton players Bradley Wright-Phillips and Lloyd Sam. The Vancouver Whitecaps are coached by a Scot, Martin Rennie, and have Kenny Miller and Nigel Reo-Coker on the roster. Robbie Earnshaw and Steven Caldwell are at Toronto (coached by Ryan Nelsen), one-time Derby tyro Giles Barnes is at Houston and Peter Walton, the former Premier League referee, was headhunted to improve refereeing standards.
Dempsey's transfer is thus a big deal. A major star returning while he still has much to offer. A three-and-a-half-year $24m (£15.5m) contract was part of the attraction, especially as he may be able to top that up in Europe on loan in the winter as MLS's other big name, Landon Donovan, has done. But, said Dempsey, "I wanted to come back when I was in my prime, not when I was past it. If I was coming back I wanted to make an impact. I'm not just coming here to chill."
Nor will be Manchester City, whose arrival in New York further suggests MLS is planning the next step. The league has many strengths. Most teams now play in new stadiums built for football, not vast bowls designed for baseball or NFL, and have solid local support. Already on a par with the French and Dutch leagues in terms of attendances (and basketball and ice hockey at home), it has designs on parity with bigger European leagues. The problem, however, is the quality, which is more obvious now than ever.
It used to be near-impossible to watch the game in the States. Now, in an indication of its growing popularity, major network NBC outbid Fox Soccer for the Premier League rights and shows wall-to-wall coverage at weekends. Champions League ties are also readily available. Set against this MLS, with its mix of superannuated Europeans, mediocre South Americans and naïve college kids, looks bad. One executive admitted they rejected the chance to piggyback on to Premier League coverage by re-arranging kick-offs for fear of the comparison.
Tucked away, the Seattle-Portland game attracted 300,000 viewers, which is about the level of Scrabble broadcasts. It is unlikely to get much better with NFL and college football about to start. By November, when MLS moves into the play-offs, it will be low down the sporting agenda.
One problem is that while clubs have built increasingly dedicated fan bases in their own cities there is no "national" club, a team like Manchester United or Juventus, Bayern Munich or NFL's Dallas Cowboys, who transcend regional support. There is also competition from the women, whose national team are more successful – the profile of Dempsey and Donovan is no higher than those of Hope Solo or Alex Morgan.
There is a new TV deal in the offing, which will kick in from 2015, when NYC FC debut. Despite low viewing figures this should be more valuable to the clubs. The increased worth of franchises, and the prospect of a loosening of salary constraints, may even persuade those half-dozen US sports entrepreneurs currently investing in the Premier League to look closer to home.