MLS made the right decision by dumping the predetermined venue for the championship game and, starting this year, awarding the match to the finalist with the most regular season points.

Look no further than the previous two MLS Cups for the striking difference in setting and atmosphere: In 2010, when FC Dallas played the Colorado Rapids in Toronto, no-shows and early-exiting fans on a gusty evening left an embarrassing number of empty seats. Last year, in contrast, the Los Angeles Galaxy happened to advance to the final at its home stadium against the Houston Dynamo — just the third time in 16 years the league final had a true home team. Home Depot Center pulsated with energy and provided a vibrant backdrop for the TV presentation. League executives were hooked.

When the new venue policy was approved last winter, the immediate issues were logistics and weather. But as the 2012 regular season winds down and the San Jose Earthquakes close in on the Supporters’ Shield as the regular season’s best side, MLS is facing the possibility of its marquee match being played at the smallest venue in the league — one better suited for a high school football playoff game than a pro championship.

Buck Shaw Stadium, the Earthquakes’ home since returning to MLS in 2008, has been an acceptable place-holder until the organization finalized plans for a new stadium. (Groundbreaking near San Jose airport is Oct. 21.) But the 50-year-old facility holds just 10,525 spectators and, situated on Santa Clara University’s small campus, might not be able to provide adequate support space and facilities for a prominent match. It certainly wouldn’t be able to meet ticket demand.

MLS Cup has never been played in a stadium that held fewer than 21,000 (Dallas twice and Columbus and Toronto once apiece).

Adding temporary seats at Buck Shaw seems plausible, but on short notice, obstacles are sure to arise.

Fortunately, the Bay Area boasts several large stadiums. Unfortunately, availability is an issue.

The natural choice is Stanford Stadium, which is on the same side of the bay 16 miles north of Santa Clara, holds 50,000 and is equipped with natural grass. The Earthquakes played there in June, drawing a sellout crowd for the Los Angeles Galaxy’s visit.

The problem: Stanford’s football team might end up hosting the Pac-12 championship game Nov. 30 — the day before MLS Cup. Like with MLS, the higher seed will host the final. Stanford, currently 3-0 and ranked eighth nationally, might remain in the running until late November. The MLS Cup finalists will be in place by Nov. 18.

There are two NFL stadiums in the area: Oakland-Alameda County Stadium and antiquated Candlestick Park. Oakland is out because the Raiders are home Dec. 2, and although the 49ers are on the road that weekend, the field at that late point in the season would probably be in rough condition.

In the U.S. Open Cup, the Earthquakes played at historic Kezar Stadium in San Francisco’s Golden Gate Park but capacity is 9,000.

Cal’s Memorial Stadium (football) has artificial turf and is too narrow, a problem also afflicting San Jose State’s 30,000-seat Spartan Stadium, the Earthquakes’ imperfect home from 1996 until 2005.

So that leaves ... AT&T Park. The sumptuous baseball stadium by the bay hosted an Earthquakes match in March. It also welcomed a U.S. national team friendly against Japan in 2006 and a friendly between Manchester City and Club America last year.

Capacity is around 41,000. The field would be configured like this. Even if the Giants play in the World Series, the stadium would have ample time to prepare for MLS Cup. It doesn’t hurt that a Giants investor has a stake in MLS (D.C. United general partner Will Chang).

Of course, the stadium issue may become a moot point. The Earthquakes could relinquish their Supporters’ Shield lead to the Eastern Conference front-runner over the next four weeks or lose in the Western playoffs. But with an 18-6-6 record, a penchant for late-game heroics and the league’s top scorer (and MVP candidate) in Chris Wondolowski, San Jose is the clear fall favorite.

Jon Busch, meet Buster Posey .