MLB.com Columnist

Richard Justice

10 most interesting storylines ... so far

10 most interesting storylines ... so far

Some things you just know. For instance, the St. Louis Cardinals are going to the postseason.

This will be the fifth straight season, and the 12th time in 16 seasons, that they've gone. Their excellence is such a part of a baseball season's narrative that it's easy to take them for granted.

Here's another one: The San Francisco Giants are going to be in the mix. They'll underwhelm you in the offseason at times. Sometimes you'll wonder what they're thinking.

Then they'll fight and claw and scrap. Like the Cardinals, the Giants are a great top-to-bottom organization that emphasizes stability and smarts.

Crawford's impressive throw

So the Cards and Giants would surprise exactly no one by meeting in the postseason for the third time in four years.

But there are things in this season we didn't see coming. Maybe we should know better than to be surprised because parity has changed everything.

Every season, there are new clubs in contention, new faces doing great things and a chaotic September awaiting.

In that way, there are no surprises. Perhaps this is a list of things we should have seen coming. For instance …

1. Astros
OK, no one -- and I mean no one -- saw this one coming. Houston has spent 110 days atop the American League West after averaging 104 losses the previous four seasons. The Astros are a young, dynamic, entertaining team playing with enthusiasm and energy. They play great defense and have a very good offense. As the season has progressed, they've developed an impressive core of toughness and confidence. General manager Jeff Luhnow should clear a space for his first Executive of the Year Award. And no manager has done a better job than A.J. Hinch.

Correa's RBI single

2. Blue Jays
They're a reminder that winning teams aren't built in one offseason, or even two. They're a reminder that there can't be just one way to acquire players. GM Alex Anthopoulos has gotten them every way possible and kept at it even when things didn't turn out the way he'd hoped the past two seasons. His team has no real weakness and seems to be sprinting toward October.

3. Nationals
Best team in baseball, we predicted at the beginning. Able to withstand all these injuries, we added at the All-Star break. Turns out, we couldn't have been more wrong. They've had a numbing injury list, but even that can't explain away the dismal play. This is baseball's most disappointing team by miles.

4. Lorenzo Cain, center fielder, Royals
Remember when Cain was considered a defensive specialist? He's still that, one of the best. Cain is also a five-tool player capable of impacting a game from every angle. With 29 doubles, 22 steals and an .873 OPS, he has played his way onto a bunch of AL Most Valuable Player Award ballots.

Cain's solo blast

5. Brandon Crawford, shortstop, Giants
Crawford has gotten better in all four of his full big league seasons. In this one, he has emerged a star. Defense was once Crawford's specialty. Now he's leading all big league shortstops in OPS (.816). Crawford is part of a homegrown infield that speaks volumes about the Giants' ability to find players and their genius at allowing them to develop at their own pace.

6. Bryce Harper, right fielder, Nationals
It was only a matter of time, right? We all knew the skills were there, that all he needed was to stay healthy as he continued to figure out things. That's what has happened. Only 22, Harper leads the Majors in OPS (1.089) and is dotted across the leaderboard with 30 homers, 25 doubles and a .452 OBP. For those who thought he'd never fulfill the hype of being a No. 1 overall Draft pick, Harper has done just that in his fourth season.

Harper's 30th home run

7. A.J. Pollock, center fielder, D-backs
Finally given a chance to play every day, Pollock has become a huge weapon on one of the highest-scoring teams in baseball. He leads the National League with 80 runs and also has 43 extra-base hits and an .844 OPS. There can't be a discussion of baseball's best center fielders without mentioning his name.

8. Kevin Kiermaier, center fielder, Rays
Kiermaier is the best center fielder in the game, and it's not even close. He was such a heralded defensive player in the Minors that the Rays played him for just one Major League regular-season game and then included him in their postseason roster. At 25, Kiermaier's offensive game is coming around. He's leading the AL with 11 triples. Kiermaier is still working on strike-zone discipline, but his defense is what keeps him in the lineup.

Must C: Kiermaier steals homer

9. Matt Duffy, third baseman, Giants
The Giants did attempt to re-sign Pablo Sandoval, so it's not like they knew how good this kid was going to be. Now they do. Duffy's defense is better than Sandoval's and so is his offense. Duffy is in the top 10 among all third basemen in an assortment of offensive categories, including OPS (fourth), hits (eighth), doubles (nine) and RBIs (eighth).

10. Carlos Correa, shortstop, Astros
Since the 20-year-old made his debut on June 8, he has led (or is tied) among all Major League shortstops in home runs (14), RBIs (38) and OPS (.897). Correa is a dynamic defensive player and carries himself with such a quiet confidence that it's OK to think of him as a young Derek Jeter. He'll be a cornerstone for the Astros for years.

Richard Justice is a columnist for MLB.com. Read his blog, Justice4U. This story was not subject to the approval of Major League Baseball or its clubs.