The chants rose from Jeld-Wen Field's Section 107 like steam. 

On the field, an amateur soccer team from California had come to town and was in the process of beating a Major League Soccer franchise, the Portland Timbers.

"You call this MLS?" went one chant coming from the stands. "This is bullshit!" went another.

The anger was rolling out of one of the most loyal fan sections in American sports. When Timbers Army members turn on their own team, you know it's very, very bad.

In the 1-0 loss to Cal FC in a U.S. Open Cup match May 30, the Timbers fired a stunning 37 shots. Only a well-placed header by Portland forward Jorge Perlaza presented the Cal FC goalkeeper with any real difficulty. Kris Boyd, the Timbers' million-dollar striker, sent a second-half penalty kick well over the crossbar.

The humiliation only underscored what Timbers fans already knew: Portland's offense has gone dry.

Not counting own goals by opposing teams, Portland has managed to score only two goals in the past six games—one by defender Eric Brunner against the Chicago Fire on May 20 and one by Boyd against the Vancouver Whitecaps on May 26.

What's going wrong? Here are a few of the factors behind the team's scoring woes:

A change of focus.

The Timbers have worked to fix the leaky defense we've reported on before (see "How the Timbers Lose," WW, April 18, 2012). Head coach John Spencer switched to a predominately defensive lineup against Sporting Kansas City on April 21, and that led to a 1-0 upset on an own goal against the previously undefeated team.

Before that match, Portland had allowed an average of 1.8 goals a match; since then, it's 0.7. Portland has three shutouts in the past six games and hasn't lost an MLS match in the past four. 

But until some offensive adjustments in the Vancouver game, the tight backfield often left the Timbers without solid opportunities to link the ball to the offense.

A lack of a finishing touch.

The heart of the Timbers' offensive difficulties, however, is the low percentage of shots they convert to goals.

This season, only 8 percent of Portland's shots have led to goals. Only three teams in the league (Chivas USA, Toronto FC, and the Philadelphia Union) are worse.

"We've taken a lot of chances," Spencer tells WW. "We've asked the midfielders to give us some creativity, and I think they've done that. Now it's just down to asking the forwards to finish some chances."

The mental thing.

Then there's the mysterious sporting ailment: a loss of nerve in front of the net.

The Timbers' tendency to misfire or overshoot is a problem that has followed the team through its two MLS seasons.

Kenny Cooper was a middling shooter for Portland in 2011. The Timbers traded him away, and Cooper is now tied as the top scorer in MLS, with 11 goals for the New York Red Bulls.

Boyd, the all-time goal-scoring leader in the Scottish Premier League, is struggling with four goals from 38 shots—the same number taken by Cooper this year.

That two very good strikers have turned cold on the Timbers' front line may suggest deeper problems.

"[S]eeing Boyd suffer the same problems as Cooper, I doubt it's just the players," said one commenter on Stumptown Footy, the popular Timbers blog, after the loss to Cal FC.

Doubts about Spencer are growing. "The squad is a shambles, our coach over his head," wrote one fan on the blog. Added another: "Newspaper headline writers are experimenting with various puns on 'axing' as we speak. 'Timbers Ax Falls on Spencer.'"

Stumptown Footy's Geoff Gibson tells WW that talk about firing Spencer is premature, and that Spencer deserves some credit for the turnaround in the team's defense this season. Gibson is sanguine about the team's future, even though many fans aren't as patient.

"There is a very vocal minority that is calling for John Spencer to be fired," Gibson says. "There's more legitimacy for the demand since the U.S. Open Cup fiasco, but I would still wager that he'll see this season out."

Chances are good that the same fans calling for heads to roll will deny they said it after the next victory.

But even with signs the Timbers might turn this season around, the waiting will remain difficult for many, and their patience may soon expire.