The days are getting shorter. The temperatures, so they claim, are dropping just a bit. Kids are back in school. And baseball is entering its best month of the season.

The poets love April's renewal. October never fails to deliver must-watch moments on a nightly basis. But for a combination of drama and volume, no month on the baseball calendar tops September.

While just about every team and every game has something worth noting, here are five of the most compelling storylines to keep track of as baseball's marathon enters its final sprint.

The Big Movers

When the A's acquired Jon Lester to go along with Jeff Samardzija, and the Tigers countered by trading for David Price, it was easy to look ahead to some delicious potential playoff matchups. But those matchups were going to come in the American League Championship Series, right?

Maybe not.

Neither team has taken off since its big acquisition, and as things currently stand, neither is even in first place in its division. If the postseason started today (those dreaded words), Oakland-Detroit would be a single-game scrap to determine who gets to face the Angels in the Division Series. Oakland is at least safe in playoff position, well clear of the chasers in the wild card race if they don't win the West. But the Tigers could realistically miss the playoffs entirely.

The A's have stopped hitting (a composite .229/.304/.359 line in August), while the Tigers have issues in their bullpen and at the back of their rotation. They certainly could both win their divisions. They could even finish 1-2 in the AL, and not meet till the ALCS. But for now, Lester and Price aren't luxury items for teams cruising into October. Instead, they're essential pieces for teams fighting for division titles.

The Mighty Royals 

If you're looking for a team to follow in September, it's a pretty easy call: root for playoff baseball in Kansas City. If recent series in Pittsburgh and Baltimore are any indication, a Division Series (or more) at Kauffman Stadium would be simply sensational.

They have a stealth MVP candidate in Alex Gordon. They have a fantastic, deep, flame-throwing bullpen. They play really good defense. But most of all, they have an absolutely starved fan base. Royals fans have put up with a lot, for a long time, and now that the team on the field is giving them something to be excited about, the K has been raucous for quite a few games.

If they actually play postseason games at that beautiful ballpark, you won't want to miss it.

The Baffling Redbirds 

On the other side of the state, the defending National League champions are enduring a genuinely puzzling year. The Cardinals have never found traction, and with the season down to its final month, it's more than past time to get rolling.

St. Louis actually leads the Wild Card race, but the Cards have been outscored on the season. For a team that has gotten some shaky bullpen work and some questionable tactical decisions, that doesn't add up at all. But here the Cards are, riding Adam Wainwright, Lance Lynn, and an offense that gets on base but doesn't do much else to playoff position.

Come October, they look like a team with an insufficient playoff rotation, a lineup that can easily be neutralized, and a manager and bullpen that can be exposed.

And yet ... say Michael Wacha comes back strong. Say Yadier Molina shakes off the rust quickly. Say the light comes on for wunderkind Oscar Taveras. Say they get a good start in the wild card game and eke out a win.

Would you want your favorite team to have to try to kill these guys off in a playoff series? I didn't think so.

One Word: Giancarlo

 If you're a baseball fan, you surely know Giancarlo Stanton's raw power. You know he's an awfully good player. But if you haven't looked at the stats in the past couple of months you might have missed the transformation. Stanton is the best player in the National League and it's not especially close.

Yes, one version of WAR suggests that Jonathan Lucroy is in the neighborhood, and another suggests that Jason Heyward is right there as well. Troy Tulowitzki, when healthy, has a heck of a case, but he's not healthy right now. In the National League, there's Giancarlo and there's everybody else.

While playing in a brutal ballpark, Stanton leads the league in on-base percentage, slugging percentage, home runs, RBIs, and walks. He's 10 for 11 in stolen bases (imagine THAT freight train bearing down on you as a middle infielder). He has maintained his status as an excellent defensive player.

A guy with all the tools has turned those tools into skills, and it is a magnificent thing to watch. The Marlins are an interesting club anyway, but Stanton makes their games must-watch. Make some time to see him do his thing.

Jeter, Jeter, Jeter

You knew you wouldn't escape him. But take heart: even if you're one of those folks who didn't think Jeter's farewell tour was up your alley, there's a bit of intrigue creeping into No. 2's final season.

The unfortunate truth is that appropriately feting Jeter and trying to make the playoffs are not entirely simpatico goals. Jeter, for whatever he may have been previously, is simply not a very good defensive shortstop in 2014. The Yankees have at least two better defensive shortstops on their roster in Brendan Ryan and Stephen Drew.

He's also hitting .266/.314/.317, which is a lot better than you or I could do against Major League pitching at age 27, never mind 40, but is well below average for a big league regular. 

Now, you may be thinking none of this is new. What is news is that Yankees manager Joe Girardi may be starting to react to at least the first issue. Jeter has served as designated hitter four times in the second half of August, more times than he had done in the previous 4 1/2 months of the season combined.

It's extremely unlikely Jeter will move out of the top two spots in the Yankees lineup anytime soon. But he has seen a few more starts away from shortstop, and it's very much something to keep an eye on down the stretch.