The Astros opened the season as one of the World Series favorites after falling to the Red Sox in the ALCS last year, and are now the largest favorites since 2007 heading into the start of the World Series on Tuesday against the Nationals

On Sunday, Caesars Sportsbook opened the Astros -235 favorites and put the Nationals as +195 underdogs. We have not seen an overwhelming favorite to win it all since the Red Sox were -240 to beat the Rockies 12 years ago. 

DraftKings Sportsbook puts their odds of sweeping at 25-1 and the Astros at +750 to take the series in four games.

The Astros and the defending champion Red Sox shared the top spot to win the whole thing before this season began, at 6-1, according to Caesars Sportsbook. Houston met expectations and is preparing for Game 1 on Tuesday, while the Red Sox did not make the postseason. 

The Astros have now made the World Series in two of the last three years, beating the Dodgers to take home the trophy in 2017. 

This is not the first time the Nationals have been overlooked this season. A rocky start made many doubt they would secure the National League Pennant, but they overcame the odds (and a 19-31 start back in May) to make their first World Series appearance. 

Washington eliminated the Brewers, Dodgers and Cardinals to get to where they are now.