Rivalry Week is upon us, which means it's a good time to review the history of some of Major League Soccer's most intense battles. Not all rivalries are equal, but each has its own unique origin story, big moments and players who command the spotlight.
New York City FC vs. New York Red Bulls
How it started
When NYCFC entered Major League Soccer in 2015, the possibility of an intense rivalry with the New York Red Bulls had plenty of people excited. Two teams separated by just a few miles in the country's biggest metropolitan area had all the makings of a regular battle for New York soccer supremacy.
It wasn't until the NYCFC's inaugural win against the Red Bulls that the heat increased to "derby" levels. The New Jersey-based club owned the first three meetings in 2015 and started the 2016 series with a 7-0 destruction of NYCFC at Yankee Stadium.
In the next meeting, NYCFC scored a 2-0 July win in front of more than 33,000 at Yankee Stadium, with Jack Harrison scoring. Since, the rivalry has been an even split with each team winning three games and the teams playing to a draw once.
Best moment
Last year's August match at Yankee Stadium produced an epic battle between two of the greatest goal scorers in MLS history. David Villa scored the first hat trick in Hudson River Derby history, while Bradley Wright-Phillips bagged two goals in a 3-2 NYCFC victory.
Villa contributed on the defensive end as well, making a brilliant play to block Wright-Phillips from close range when the Red Bulls striker had a chance to give his team the lead.
The key man
There's only one choice for the most influential man in the Hudson River Derby, and it's Wright-Phillips.
The Englishman scored the first goal in the history of the rivalry (inside of five minutes, no less) and has scored an additional 10 since. His total of 11 goals in 12 games in all competitions outpaces the total of the second-leading scorer on the list, Villa, by seven goals.
The quote
"I was brought up to not like Man United. I would hope my children do not like NYCFC." -- Bradley Wright-Phillips
LA Galaxy vs. LAFC
How it started
It's still just Year 1 of the L.A. rivalry creatively dubbed "El Trafico" by the fans, but the seeds of something special have been planted. Friday's edition will be the third and final meeting of the season (barring a playoff clash) and will need a heavy dose of drama to match the first two games in the series.
Zlatan Ibrahimovic's arrival in MLS and L.A. coincided with the first-ever El Trafico game on March 31. The Swedish superstar entered the match at the StubHub Center with his new team down two goals, scored twice in 15 minutes, and led the Galaxy to victory.
The best moment
The best moment the L.A. derby has offered so far can only be Ibrahimovic's midfield strike to level the inaugural edition. In front of a full house at the StubHub Center, Ibrahimovic lived up to every expectation with an absolute wondergoal. LAFC goalkeeper Tyler Miller will want to forget the moment, but for MLS fans in North America and soccer fans around the globe, the goal and that moment sparked an interest in a crosstown matchup that will carry over to each new edition.
The key man
Through two games, it's actually LAFC's Mexican star Carlos Vela who has the most goals in the rivalry with three. But the choice for the most influential player has to go to Ibrahimovic, the man who stole the show back in March and helped lead another comeback in a draw at Banc of California Stadium on July 26.
Ibrahimovic's dramatic arrival on the scene and influence in the 2-2 draw at Banc of California Stadium put him at the center of the evolving contretemps, but it's the Swede's personality and penchant for cutting and audacious statements that will draw the most attention.
The quote
"This is still fresh, this derby. LAFC is a new team. We cannot talk historically about previous games, only about the game we had [in March], but in time [there will be] more talks about it, what happened before, and you get new moments from that derby." -- Zlatan Ibrahimovic
Seattle vs. Portland
How it started
There are older rivalries between teams born in the MLS era, but no American soccer clash has more history than the Cascadia Derby between the Sounders and Timbers. The first match between the clubs took place back in 1975; that same year, the Timbers knocked the Sounders out of the NASL playoffs.
Both clubs played in the old North American Soccer League, then when that league ended, revived the derby in the lower divisions. After a few seasons of meeting only in the U.S. Open Cup, the rivalry moved to MLS in 2011 when the Timbers joined Seattle in the top division.
The easiest way to explain the origins of the Sounders-Timbers rivalry is simply that when it comes to everything -- soccer included -- Seattle and Portland just don't get along.
The best moment
The biggest stakes for any Cascadia Derby came in the MLS Cup playoffs back in 2013. A conference semifinal series between top-seeded Portland and fourth-seeded Seattle started at CenturyLink Field, where the Timbers had never led, much less won.
On the back of goals from Ryan Johnson and Darlington Nagbe, with a big hand from goalkeeper Donovan Ricketts, Portland won the match 2-1. The Timbers would go on to win the second leg 3-2 and take the first -- and thus far, only -- MLS playoff meeting between the two teams.
The key man
Clint Dempsey has a penchant for scoring goals in the rivalry and he doesn't hesitate to let Timbers fans know about it when he does. In 14 games against Portland, Dempsey has scored nine goals. The co-all-time-leading scorer in Sounders history has scored more against the Timbers than any other team.
Dempsey is filling a substitute role for the Sounders at this point in the season, but it would be folly to write off the possibility of him playing a big role in any game where Seattle takes on the Timbers.
The quote
"All I got to say is, now that we won one, Portland can't say s---!" -- Clint Dempsey after Seattle's 2016 MLS Cup title