2. What can prevent the Cubs from winning the World Series again?

It’s silly to ask if the Cubs can repeat as World Series champions. Of course they can. Last year they became the first team to start five or more players under age 25 in four World Series games, including a record six in Game 2. All are back except 24-year-old outfielder Jorge Soler, who was traded to Kansas City in exchange for one of the best closers in baseball, Wade Davis. Chicago also ranked second in the league in runs last year without slugger Kyle Schwarber, who returned from his torn ACL in time for the World Series. This is still the best team in baseball.

The key for the Cubs will be maintaining their extraordinary run prevention infrastructure that’s now been in place for two years. No team has been better at marrying scouting and quantitative analysis when it comes to preventing runs. But the backbone of the system is reliable starting pitching. In 2016 Chicago became the first team since the 2013 Reds to post a second straight season with four pitchers making 30 starts.

Now the Cubs will have to defy the age and workload curve after two postseason runs. Jon Lester, who pitches at age 33 this year, and Jake Arrieta, who will be 31, have each made 71 starts the past two years, postseason included, while combining for 925 1/3 innings.