10 spots in the Round of 16 at the World Cup have been locked up, and six spots remain across the next two days.We have another three matches to watch and bet on today, so let's dive into my best bet for each of them.Best World Cup Bets TodayOdds via Caesars SportsbookSpain -1.5 (-105) vs. AustriaCroatia +0.5 (+107) vs. PortugalAlgeria to Advance (+154) vs. SwitzerlandSpain vs. Austria PredictionNot only were Spain the pre-tournament favorites, but they finished the Group Stage with the best expected goal differential per 90 minutes at +1.61. Their 0-0 draw against Cape Verde has led some people to believe that they aren't as good as originally expected, but the underlying numbers have shown that they are head and shoulders above the majority of teams in this tournament, including Austria. The Austrians finished the group stage with an expected goal differential of -0.23 per 90 minutes.I'm willing to bet on Spain running away with the win in this one.Best Bet: Spain -1.5 (-105)Portugal vs. Croatia PredictionI predicted that Portugal would fail to meet expectations in this tournament due to their insistence on utilizing Cristiano Ronaldo, despite his play having significantly regressed in recent years due to age. Not only does it hurt their production, but it's clear he has hurt the team's chemistry as well.Croatia is in the opposite situation. They're a team that knows how to play as a unit, evidenced by the last two World Cups. They may not win, but I think there's a chance this match at least goes to extra time, which would cash this Croatia +0.5 bet at +107.Best Bet: Croatia +0.5 (+107)Switzerland vs. Algeria PredictionI was high on Algeria coming into this tournament as an African team that could go on a deeper run than people expect. It's time for me to back them in the Round of 32 against a Switzerland team that I'm not convinced is much better. Switzerland had a +0.75 expected goal differential per 90 minutes while playing against the likes of Qatar, Canada, and Bosnia & Herzegovina. Meanwhile, Algeria had an expected goal differential per 90 minutes of +0.36 while playing against Argentina, Austria, and Jordan.There's enough there for me to take a chance on the Algerians to advance at +154.Best Bet: Algeria to Advance (+154)Follow Iain on X and InstagramBet $1, get 100% profit boost on your next 10 bets when you claim your Caesars Sportsbook new user promo using code ‘SICZRDYW’. Sign up, deposit at least $10, and place your first real-money wager. Up to $25 max bet per boost.Odds refresh periodically and are subject to change.If you or someone you know has a gambling problem and wants help, call 1-800-GAMBLER.You can check out all of Iain's bets here!Add us as a preferred source on GoogleFollow