The 2018 World Cup quarterfinals get underway with multiple must-see fixtures. Eight teams will battle to survive and advance until one champion is crowned in Russia 2018. With the 2018 World Cup field of eight locked in, it's time to fill out your 2018 World Cup bracket. You can pick which teams advance based on multiple factors, or you can trust a successful model that has been proven to work. That'll give you the advantage you need to take down your 2018 World Cup bracket pool.

So before you lock in your 2018 World Cup bracket on FIFA's official site or anywhere else, you need to see what European football expert David Sumpter has to say.

Sumpter is an applied mathematician who wrote "Soccermatics" -- the book that shows how math works inside the game. Together with experienced analysts, Sumpter developed the powerful Soccerbot model.

The Soccerbot reads current odds and all team performance data, calculates key metrics and predicts upcoming matches. In the two-and-a-half seasons since it was born, the Soccerbot is up 1,800 percent on bookmakers' closing odds. That's right -- 1,800 percent! 

The Soccerbot has impressed during the knockout stage: On Sunday, it correctly predicted draws for Spain-Russia (+280) and Croatia-Denmark (+225). In fact, it nailed six of the eight knockout stage games so far. Earlier, the model nailed draws for Argentina-Iceland (+385) and Brazil-Switzerland (+360) and predicted Iran upsetting Morocco at +275, just to name a few of its big calls. Anyone who has followed it is way up. 

Now, the Soccerbot analyzed every potential knockout matchup and revealed its optimal 2018 World Cup bracket.

One shocker: Uruguay, which is unbeaten at the 2018 World Cup, doesn't advance past the quarterfinals.

Uruguay heads into its quarterfinal match against France having won its first four games of the World Cup. It's the first time they've done so since 1930. The Uruguayans were the only team at the 2018 World Cup to win all of their group stage matches without conceding a goal. They were the first team to pull off that feat since Argentina in 1998.

However, Uruguay will have a tough task in defeating France to advance to the semifinals. France is unbeaten in its last nine World Cup matches against South American nations. Despite Uruguay's form entering the quarterfinals at the 2018 World Cup, the model says it won't reach the semifinals.

Sumpter's optimal bracket has also identified its 2018 World Cup champion. Nailing this pick is the key to winning your World Cup bracket pool.

So what is the optimal bracket for the World Cup Challenge? Visit SportsLine now to see which teams you need to be all over in your World Cup brackets, all from the model that's returned an 1800 percent profit on bookmakers' closing odds.