Welcome to the RealClearSports Weekend Warmup!

We are just 13 days away from the NFL regular-season opener, and football rules all else this time of year. From domestic violence to CTE, the NFL never seems to be free from controversy these days. And yet the action and drama on the field still holds a breathtaking charm. The passion expressed by fans is still part of the great American tradition.

With 32 teams competing for 12 playoff spots (and it seems at least three teams competing for the worst record of all time), this year promises to be full of excitement. With that in mind, RCS editor Ben Krimmel put together his rankings of the Top 10 NFL Contenders of 2017.

NFL

The third and final preseason game for each team will mark every fan's last opportunity to see their team's starters take the field before the regular season begins (and pray that nobody gets hurt). On Friday night, Andy Reid's Kansas City Chiefs travel to face Pete Carroll's Seattle Seahawks (8 p.m. ET on CBS), and the first battle of Los Angeles takes place Saturday as the Chargers face off against the Rams (8 p.m. ET on CBS).

A Sunday triple-header will see the Chicago Bears (who are still looking for a quarterback to emerge between Mike Glennon, Mark Sanchez, and Mitchell Trubisky) play Marcus Mariota's Tennessee Titans (1 p.m. ET on FOX); Washington will host Cincinnati (4 p.m. ET on FOX); and the nightcap will feature the San Francisco 49ers taking on the Minnesota Vikings at U.S. Bank Stadium (8 p.m. ET on NBC).

College Football

Think of this weekend as the disappointing cheese course at the start of a big meal: The games aren't great, they may give you sports indigestion, but you will more than likely find yourself consuming them all anyway.

Saturday's notable games include Oregon State traveling to Colorado State (2:30 p.m. ET on CBS Sports Network), Portland State vs. BYU (3 p.m. ET on ESPN), and No. 19 South Florida taking on San Jose State (7:30 p.m. ET on CBSSN). And to cap things off, Rice will do battle with No. 14 Stanford from Moore Park in Sydney, Australia (10 p.m. ET on ESPN).

Boxing

Finally, Floyd Mayweather and Conor McGregor will meet in the ring for 12 rounds of boxing from the T-Mobile Arena on the Las Vegas Strip. In order to score a massive upset over the defensive Mayweather, UFC fighter McGregor will have to get rough and creative. And in RealClearLife, two experts explain why Mayweather will remain undefeated. See Friday's weigh-in on FS1 (6 p.m. ET) before Saturday night's fight, available via pay-per-view (main card starts at 9 p.m. ET).

MLB

With nine teams in the American League vying for a Wild Card playoff spot, the postseason picture in the Junior Circuit is likely to remain wide-open for the remainder of the season.

The resurgent New York Yankees (who brawled with the Detroit Tigers on Thursday) have a chance to make up some ground in the AL East this weekend and solidify their playoff chances with a three-game set against the Seattle Mariners. Friday's action will feature CC Sabathia taking the mound against M's lefty Ariel Miranda (7 p.m. ET on MLB Network); Sonny Gray will face struggling starter Yovani Gallardo on Saturday (1 p.m. ET on MLBN); and on Sunday afternoon Masahiro Tanaka will go up against Canadian southpaw Andrew Albers (1 p.m. ET on TBS).

On Saturday, the Royals will throw Jason Hammel against the Indians' Mike Clevinger (7 p.m. ET on FS1). And finally, the woeful New York Mets will face the first-place -- and banged-up -- Washington Nationals (Saturday at 4 p.m. ET on FS1, and Sunday at 8 p.m. ET on ESPN).

NBA

The NBA season is still months away, but the Cleveland Cavaliers trading Kyrie Irving to the Boston Celtics for Isaiah Thomas rocked the basketball world this week. Editor Cory Gunkel explains why Kyrie was the deal's real winner.

PGA

The first tournament of the FedEx Cup Playoffs, the Northern Trust, will showcase the best players in the world competing for a $10 million prize at the Glen Oaks Club in Old Westbury, New York. (Coverage begins Friday on Golf Channel from 2-6 p.m. ET, with Saturday's coverage on CBS running from 3-6 p.m. ET, and Sunday from 2-6 p.m. ET.)

Soccer

The soccer season rolls on with another jampacked weekend across the world that begins Friday night in MLS with the Hudson River Derby, as the New York Red Bulls host New York City FC (7 p.m. ET on ESPN).

Saturday's Premier League triple-header starts with Manchester City heading south to play Bournemouth (7:30 a.m. ET on NBCSN), followed by Chelsea taking on Everton (10 a.m. ET on NBCSN), and ending with Jose Mourinho's Manchester United competing to maintain their perfect start to the season in a showdown against Leicester City (12:30 p.m. ET on NBC).

In Germany, Bayern Munich will head to Werder Bremen (9:30 a.m. ET on FS1), and later on Saturday the pride of Hershey, Pennsylvania, Christian Pulisic, will accompany his Borussia Dortmund teammates as they take on Hertha Berlin (12:30 p.m. ET on FS1).

Sunday's action begins with unbeaten West Bromwich Albion (yes, some English teams have peculiar names) taking on Stoke City (8:30 a.m. ET on CNBC). And fresh off their big Champions League win, Liverpool will host Arsenal at Anfield (11 a.m. ET on NBCSN).

In MLS, the San Jose Earthquakes travel to Carson, California, to play the LA Galaxy (7 p.m. ET on FS1), followed that evening by the best rivalry in all of American soccer, the Cascadia Derby, featuring the Seattle Sounders against the Portland Timbers (9:30 p.m. ET on FS1).

On This Day

On this date in 1996, Tiger Woods became the first golfer to win the United States Amateur championships for three consecutive years. The lead from the New York Times the next day: "In a comeback as dramatic as any in the annals of golf, Tiger Woods roared into history today."

Three days later, Tiger Woods would turn pro and say, ''I guess, hello, world."

Before Woods even acquired his PGA Tour card he had gained endorsement contracts for $43 million. Tiger would of course go on to win the Masters four times, the U.S. Open three times, the British Open three times, and the PGA Championship four times.

Check RealClearSports.com throughout the weekend for coverage of the opening weekend of college football, NFL preseason games, Mayweather vs. McGregor, and more. Follow us on Twitter @RealClearSports and join the conversation on Facebook.