It is the parlor game that has every Nationals fan irrationally excited. Except that their hopes might not be so irrational at all. Bryce Harper had maybe the best season of any 19-year-old in baseball history. What is his encore at age 20? After all, Angels phenom Mike Trout took a massive step forward after he put his teenage years behind him.

Harper won the National League rookie of the year award thanks to a .270 batting average with 22 home runs and 59 RBI in 533 at bats in 2012. His OPS was a solid .817. He also had 26 doubles and nine triples and stole 18 bases.

Trout is 14 months older than Harper and will turn 22 in August of this season. Harper won't be 21 until Oct. 16. The Angels' outfielder batted .326 with 30 home runs and 83 RBI last season. He had 27 doubles and eight triples with 49 stolen bases. Those numbers seem extreme even for Harper. But he does have some advantages headed into his second full season.

First -- he'll get an extra month of plate appearances if he stays healthy. Harper wasn't promoted until late April last season and that was simply because the Nats were an injured mess. But he quickly adapted. It probably won't hurt that Harper is moving off center field, a more demanding position mentally and physically than left, where he takes over for the departed Michael Morse.

With a better lineup around him -- Jayson Werth was out until August last summer and Denard Span was playing for the Twins -- Harper should have more opportunities to drive in runs. It is expected that manager Davey Johnson will bat his lefty slugger in the No. 3 spot this season and bump Ryan Zimmerman down a spot to cleanup.

But can Harper improve on his strikeout and walk rates? Trout walked 67 times and struck out 139 in 559 at bats. Harper walked 56 times and struck out 120 times. They were about equal there. Both players have the opportunity to do better. And if Harper does then his overall numbers should balloon as well. The only question: How high?

- Brian McNally