With September comes not just an increase in Earth Wind & Fire airings but an increase in urgency across the Major League landscape.

Whether you're one of us who dwell on every bit of minutiae that makes up the long slog of the 162-game schedule or just a casual observer who latches on when the stakes are raised, the pulse-quickening final playoff push is always great theater. And with great theater comes great storylines.

Here are 10 big ones going into baseball's final month.

The AL East

Has to be the most captivating division race, given that it legitimately includes three clubs, all of whom are going to bump heads frequently down the stretch. In fact, 16 of the final 24 days on the calendar will feature a game involving some combination of two of these three clubs. So that'll be fun.

Do the Red Sox have enough in the bullpen to survive (would have been impossible to predict their season would rely so much on Clay Buchholz in the setup role)? Do the Orioles have enough in the rotation? Will the Blue Jays be able to nail it down if Jose Bautista somehow gets banged up again or Aaron Sanchez runs out of bullets?

Clayton Kershaw's impact on the NL West

The Dodgers and Giants have six games left against each other in a tight race, including the final three of the season at AT&T Park. San Francisco's downward spiral, built on an unreliable back end of the rotation and a lack of thump in the middle of the order, in the second half of an even year has been an unexpectedly bewildering storyline all its own.

But nothing would impact this race so much as an effective Kershaw, who hasn't pitched in a game since June 26 because of a herniated disk in his back. He threw a simulated session Tuesday and will likely make one Minor League rehab start before rejoining the Dodgers.

Other injury X-factors

There are ton of them involving teams on the bubble.

Chris Tillman is no Kershaw, but he's the closest thing the Orioles have got, and his return from shoulder issues will be closely monitored in the AL playoff picture. Wade Davis will be back soon to make a great Royals bullpen even better. Jordan Zimmermann and Nick Castellanos should return in mid-September to a Tigers team that could put that boost to use in the rotation and lineup. The Red Sox were getting nice production from rookie Andrew Benintendi before he went down, so his potential return would help. The Cardinals hope to get healthier in their rotation and hope Aledmys Diaz can return in time to spark their offense in the home stretch. The Pirates really need this Gerrit Cole injury to be a short-term thing.

The biggest injury X-factor of all (physically) is Giancarlo Stanton, who is trying to get back from a groin injury in time to power the Marlins in their bid for an NL Wild Card. Alas, it's still possible that injury -- like the Mike Fiers fastball to the face in 2014 and the broken hamate bone last June -- ends his season.

Wild Card wildness

The expanded format has created a new tradition of teams with no business being in contention … being in contention.

This year, the Yankees fit that formula, having dealt away Andrew Miller, Aroldis Chapman and Carlos Beltran, only to improve (and Gary Sanchez's Babe Ruth impersonation has obviously helped). The Mariners are also in that mix, and they come with the added intrigue of a 15-year playoff drought that stands as the longest in the game. The Marlins are still hanging around without Stanton, the Pirates are still hanging around despite having zero members of their Opening Day starting five in their current rotation and the Astros started out 7-17 but ain't dead yet.

And then there are 2015's AL and NL pennant-winners …

Fall Classic fallout?

Will last season's two World Series clubs both get shut out of October? It's only happened twice in the Wild Card era. The 2006 White Sox and Astros and the 2007 Cardinals and Tigers weren't able to advance after claiming a pennant the prior year (though it is worth noting that, had the second Wild Card slot been in effect, the '06 White Sox would have claimed it outright and the '07 Tigers would have tied for it).

The Royals have been trying like hell to avoid such a fate, with their praying mantis-aided upswing a captivating late-season story. Because of their postseason pedigree and great 'pen, they are a team no other club wants to see advance. The Mets, meanwhile, have been battered by ill health all year but are very much mathematically involved.

Both of these clubs caught a break in the September scheduling: The Mets have just 10 games left against teams with winning records, while the Royals have 12 (and the Royals still have 17 home games left).

The awards races

I wrote recently about some of the strange or unexpected storylines emanating out of the races. In the short time since that column was posted, Sanchez has done even more to legitimize his AL Rookie of the Year case, Kyle Hendricks has further separated himself in the NL Cy Young field and people continue to give Mike Trout nowhere near as much love as he deserves in the MVP discussion. As is the case annually, there's a good chance we'll see legit separation in these waning weeks, particularly with the emphasis so many voters, rightly or wrongly, still place on postseason placement.

But wow, that AL Cy Young race, in particular, is a beautiful mess. Cole Hamels, J.A. Happ, Rick Porcello, Corey Kluber, Chris Sale, Jose Quintana, Justin Verlander, Masahiro Tanaka, Aaron Sanchez, Danny Duffy (did I miss anybody?) all have one metric or another supporting their case. Who will emerge as the hot hand?

Rest vs. rust

It's the classic catch that comes with divisional clout, and the Cubs, Nationals and Rangers - all of whom take large and likely insurmountable advantages into the final month - will have to find the right balance before the Division Series begins.

The Cubs, whose bid for the Majors' most wins since the 2001 Mariners will qualify as a storyline unto itself, have had the least amount of rotation turnover of the three clubs. So it makes sense for Joe Maddon to go with a six-man group to build in added breathers, and the Cubs also need to iron out Jake Arrieta's command issues before his eventual Game 1 assignment.

The Nationals obviously hope to avoid any setbacks with Stephen Strasburg and his elbow, because starting pitching health has been an issue for them. And the Rangers could really use some rest for their overworked bullpen, so the roster expansion -- and the return of Colby Lewis to the rotation -- could help that effort.

The AL Central

The gap could still close quickly here, as the division-leading Indians still have 13 games remaining against the Tigers and Royals.
 
To fend those clubs off, the Indians will have to get more consistent starting pitching than they have in the second half. The rotation has long been billed as the backbone of this club, but, if you go back to the end of their 14-game winning streak on July 1, the Indians' rotation ERA in that span is north of 5. So they need Carlos Carrasco, Danny Salazar and Trevor Bauer at their best down the stretch if they are going to live up to the narratives about everything coming up Cleveland in the wake of the Cavaliers' long-awaited NBA title.

Home runs

A fascinating statistical subplot comes to a head here in the final month, as Major League hitters (unknowingly) vie for an all-time record.

The rate of home runs per game through Tuesday was 1.16, just the slightest tick below the all-time mark of 1.17 in 2000. And actually, the rate of at-bats between home runs (29.34) is the lowest of all-time. So that means we have a very real chance of seeing the most home runs we've ever seen hit in a single season. In 2000, which of course was the height of the so-called "steroid era," there were 5,693 long balls in all. The 2016 season had so far produced 4,595.

So seriously, how fast can Giancarlo Stanton get back?

Callups!

In our increasingly farm-system-savvy society, this stuff rates as exciting. And as usual, the also-rans are in the best position to provide meaningful playing time for prominent prospects, which means we'll probably see a decent amount of Hunter Renfroe and Manuel Margot in San Diego. Maybe Lewis Brinson in Milwaukee, Jesse Winker in Cincinnati, Ozzie Albies in Atlanta and J.P. Crawford in Philly.

But yeah, some callups could impact the races. Yoan Moncada (Red Sox) leads the list, because he's tearing up Double-A and Boston needs the help at third base. Also: Joey Gallo (Rangers), Lucas Giolito (Nationals), Tyler Glasnow (Pirates), Jose De Leon (Dodgers). Oh, and the Royals will bring up speedster Terrance Gore and hope he can (literally) steal them a win or two, because they do that every year.

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Anthony Castrovince is a Sports on Earth contributor, MLB.com columnist and MLB Network contributor. Follow him on Twitter @Castrovince.