Rankings/List

The MLB Playoffs have reached the Championship Series and the matchups in the American and National Leagues have been set.

Before we delve into the top 10 players remaining, let's set the ground rules.

Just like that, we're down to four. 

Both the American League Championship Series and National League Championship Series will begin this weekend, as the Toronto Blue Jays, Kansas City Royals, Chicago Cubs and New York Mets will vie for the right to appear in the World Series. Over the next few slides, we'll identify 10 X-factors that will determine which teams face off in the Fall Classic.

What is an X-factor? There's really no clear-cut answer to that. 

With a sighing exhale of relief, the Toronto Blue Jays and Kansas City Royals have survived.

Both teams’ American League Division Series were pushed to fifth and deciding games. At times in each series, the Blue Jays and Royals both looked left for dead before their incredible resurrections shoved them into this American League Championship Series, ripe with the league’s two best regular-season records.

We are completely through all but one Major League Baseball postseason division series and have plenty to take away from all four series and all eight participants.

Five teams in this year’s round were completely absent from the postseason a year ago, and those clubs have demonstrated how their systems have developed and acquired talent. They all have the potential to be legitimate threats to future World Series championships.

The do-or-die, win-or-go-home sporting event is the pinnacle of athletic drama.

It creates undeniable excitement before kickoff, tipoff, the puck drop and first pitch. Pins, needles, sweaty palms and butterflies are all in play when one game defines an entire season.

On Wednesday, Major League Baseball gives us two such contests.

It may be a small sample size, but slumps in October are often magnified. In the 2015 postseason, there are a handful of struggling MLB stars who must play better before their teams face an abrupt exit from the festivities. 

Obviously, an unattractive stat line will always catch the eye of fans and pundits alike. But the players on this list have more in common than a bad start to the postseason. Each player is crucial to his team's success, which makes his struggles an even bigger issue. 

The youthful Chicago Cubs are just one win away from the National League Championship Series, but the upstart squad is going to have to get past the most experienced postseason starter in baseball first.

John Lackey, who gets the nod for the St. Louis Cardinals in this must-win clash, has started 19 games in October. As Jayson Stark of ESPN.com notes, that makes Lackey the leader in that department among all active big league starting pitchers.

The early poll results are in, and they indicate this year's Major League Baseball postseason is rife with drama, intrigue and controversy as the Division Series kick off.

The No. 1 story of the early going has been Chase Utley's ugly slide that broke Ruben Tejada's leg while helping the Los Angeles Dodgers tie their series against the New York Mets. The aftermath of it all, mainly Utley's suspension, has sparked all sorts of reaction regarding the slide itself, the punishment and sliding rules along with their enforcement.

Playoff baseball is finally in swing.

Each of the eight teams in the MLB Division Series have earned a spot in the tournament for one reason or another, and now it's time for them to fight forward en route to the World Series.

The following list highlights keys to victory for each team—and an aspect that will potentially hold each of them back. 

As always, feel free to defend your colors in the comments section below. 

Let's do this.

It all comes down to this. After looking at the best players at each position over the last few weeks, the B/R MLB 300 is now ready for its final act: putting everyone together on the same list.