Take an in-depth look at the cities vying for MLS's next four expansion berths, from all aspects of their respective bids.

MLS was a very different place just 10 years ago, when the league’s dozen clubs attracted around 15,500 fans per game.

The first expansion teams of the 21st century, Real Salt Lake and Chivas USA, were in their sophomore seasons in 2006. The former was launched by Dave Checketts, a well-known sports executive and University of Utah graduate who awkwardly decided to name his new club after Real Madrid and base it in a small market with next to no soccer tradition—Salt Lake City. MLS wasn’t in any position to say "no."

The latter was started by Chivas de Guadalajara owner Jorge Vergara, a capricious and controversial Mexican billionaire who made his fortune selling dietary supplements. He was convinced fans across Southern California would flock to support a team wearing the Guadalajara crest on its jerseys. MLS wasn’t in any position to say "no."

Checketts and Vergara each paid some $7.5 million to join the league. In 2006, Toronto FC was preparing for its inaugural campaign the following year. MLS’s first Canadian entrant spent more—around $10 million—for the privilege.

Those numbers seem impossibly quaint now, like when a grandparent reflects on the days when a few thousand dollars bought an entire house. MLS attendance during the 2016 season surpassed 21,600 per game. Only one club, FC Dallas, failed to beat the 2006 league average. There will be 22 teams in 2017 as the Uniteds Minnesota and Atlanta take the field, and those following them will have to pay $150 million just to get a foot in the door. Sponsorships, a stadium, a proven fan base and more will be expected along with the expansion fee. And the line to get in is long.

Ten years ago, MLS was desperate. Recently, it revealed a list of 10 markets vying to be awarded one of the four slots that will take league membership to 28 (it’s still assumed Miami will be No. 24), with another two cities, Phoenix and Indianapolis, joining the field as late entrants. It’s a race with considerably more intrigue than the league’s regular season, from which more than half the teams move on to the MLS Cup playoffs. The stakes are higher as well.

MLS set a Jan. 31, 2017, application deadline and is committed to identifying teams No. 25 and 26 by next fall.

Amid the expansion arms race, Planet Fútbol will take a closer look—one by one—at each prospective MLS market and delve into its strengths, weaknesses and expansion prospects.

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