Since the L.A. Galaxy ushered in the Designated Player era with David Beckham’s ballyhooed signing back in 2007, we have all argued about whether spending big for stars was “essential” or merely “helpful” in the MLS title chase?

Oddsmakers have just provided a little more food for thought in the ongoing debate.

The Westgate Las Vegas Superbook this week posted MLS championship odds for 2015. (Thanks to ESPN researcher Paul Carr for the heads-up on this one.)

The wise guys out West like L.A. to repeat as champs (3-1 favorites). If anyone can win four MLS Cups in five seasons, fabulously unprecedented in the 20-year-old league, it’s that cagey ‘ol Bruce Arena.

Following the Galaxy, the oddsmakers like Seattle (9-2), New England (8-1) and D.C. United (9-1).

No big surprises. Here is where things get interesting – and what we’re talking about today: Right alongside Toronto, the New York Red Bulls and Columbus at 15-1 odds, we see New York City FC. That would be “expansion” NYCFC, of course.

Not too far behind that group is the league’s other expansion side for 2015, Orlando City, who get 25-1 odds.

So the books like Orlando City’s chances over seven established MLS clubs. And they like Jason Kreis’ NYCFC bunch better than 11 clubs. That’s more than half the field! Even allowing for bookmakers’ quirky chemistry (that odds are more or less set to balance the money and not always an outright forecast), there is just one explanation for the favorable light shining on two expansion teams: that they are both spending generously in the DP market.

See, history says that MLS expansion sides are hardly hell bent for early success. First-timers have mostly struggled predictably. Oddsmakers are no dummies; they know the history.

But past expansion clubs didn’t include a World Cup winner on roster (NYCFC’s David Villa and Orlando City’s Kaka). Frank Lampard and Mix Diskerud will join Villa at Yankee Stadium as highly paid potential game-changers.

Still, talented as they are, the Kakas and Villas and Lampards can’t cover the roster gaps inherent in expansion clubs. For instance, Kreis has some reliable MLS performers, such as defenders Jason Hernandez and Chris Wingert. But they just don’t have enough of them – and will certainly struggle once the inevitable injuries force Kreis to reach deeper into his squad.

Same for Adrian Heath at Orlando City FC, where Amobi Okugo and Aurelien Collin are center backs around whom plenty of MLS teams could happily build. But past that? A weed-out process is coming for a few roster hold-overs from the Lions days in USL Pro.

Depth, and that issue of sorting out which players can or cannot pass muster at an advanced level, tends to undercut expansion clubs along the way.

Of the last seven teams to join MLS, only Seattle finished better than 6th in their conference’s standings. The Sounders placed third in 2009 – and it was a strong third, just a point behind Los Angeles and Houston. But remember that Seattle was a willing spender straight away, signing Arsenal-ex Freddie Ljungberg for Rave Green duty. Meanwhile, Montreal, Portland, Vancouver, Philadelphia, San Jose and Toronto all finished sixth or worse in the standings in their initial MLS campaign.

Even including Seattle, those seven MLS expansion sides (all of the league’s expansion clubs of the last 10 seasons) averaged 9 wins. That’s not even including Chivas USA and Real Salt Lake, clubs that combined for nine wins in 2005, the year they joined MLS.

As a point of reference, MLS playoff teams averaged 15.5 wins last year.

Final word here: If you are heading to Vegas anytime soon, D.C. United (9-1) might be the best wager on the board, worthy of an Andrew Jackson or two (which will help keep you tuned in through the playoffs, even if you’re team doesn’t get there).

There’s a lot to like about United (who I got to see workout in Austin over the weekend), so long as a striker steps forward with 12-14 goals, and so long as they keep the Euro-suitors away from 2014 MLS Goalkeeper of the Year Bill Hamid a little while longer.

Editor’s note: Steve Davis writes a weekly column for World Soccer Talk. He shares his thoughts and opinions on US and MLS soccer topics every Wednesday, as well as news reports throughout the week. You can follow Steve on Twitter at @stevedavis90. Plus, read Steve’s other columns on World Soccer Talk.