Is the NL Central Threatening the AL East's Throne in 2013?

If we were to re-imagine Major League Baseball divisions as historically significant times and places, the AL East would have to be Ancient Rome, right?

Yeah, sounds about right. Ancient Rome was characterized by prosperity and power, and that's pretty much the AL East in a nutshell.

But look there! A power is rising, and it's in the vicinity of the NL Central!

Three of the six best records in baseball belong to NL Central clubs: the St. Louis Cardinals, Cincinnati Reds and Pittsburgh Pirates. They've been terrific, and they've done it without a heaping helping of games against the Houston Astros to boot.

So is the AL East still the Ancient Rome of baseball, or is the torch being passed to the NL Central? We certainly must have an answer to this question, and that calls for immediate discussion.

There's one thing the AL East has tended to have throughout the last decade and still has in spades this year, and that's depth.

If we take a look at some average winning percentages, with an assist from Baseball-Reference.com:

Yes, much of the AL East's success over the last decade and in the last five years can be chalked up to the New York Yankees and Boston Red Sox, but they shouldn't get all the credit.

The Toronto Blue Jays have tended to be a decent team, the Tampa Bay Rays have been annual contenders ever since 2008 and the Baltimore Orioles awoke from their slumber last year and are still good in 2013. Consistently awful teams have been a little harder to come by in the AL East.

The pattern is holding this year. The Red Sox, Orioles, Yankees and Rays are all comfortably over .500, while the Blue Jays are somewhere in between awful and mediocre with a record of 29-36.

It's different in the NL Central. The Cardinals, Reds and Pirates are great, but the Milwaukee Brewers and Chicago Cubs are ugly-duckling-ing the place up. They're two of the five worst teams in the league, and are holding the division's combined winning percentage down.

That's a lock to continue, as hope is a weird concept in Chicago and Milwaukee these days. And since the Yankees, Rays and Orioles all contended last year and the Red Sox have been reborn in 2013, we can also count on the AL East maintaining its depth until the end of the season. 

When the dust settles, the AL East should still stand out as baseball's deepest division. There's no crown for that or anything, but at the very least it'll be something for us fans to discuss when we're feeling in an argumentative mood (and aren't we always?).

But we can't stop this immediate discussion there. It can, after all, be argued that a "powerhouse" division is defined less by depth and more by the powerhouse teams in it. To that end, the NL Central has the AL East beat.

Combined, the Cardinals, Reds and Pirates have a record of 122-77. That's a winning percentage of .613 compared to a combined winning percentage of .566 for the four good teams in the AL East. The top three of those only have a winning percentage of .577.

But wait, there's more. 

Combined, the average run differential for the three NL Central contenders is plus-60. The four AL East contenders have an average run differential of about plus-30, half as good.

Yeah, a bit of an unfair comparison, but telling all the same. The worst run differential among the three NL Central contenders belongs to the Pirates at plus-14. That's better than what the Orioles (plus-12) and Yankees (plus-10) have mustered, and isn't that far off from the Rays' plus-20.

Then there are the Cardinals, who are simply ridiculous. They already have a run differential over 100, which is what happens when a team leads its league in runs scored and all of baseball in ERA. Their starters, in particular, have been brilliant with an ERA of 2.74.

Cincinnati's starters haven't been too shabby in their own right. Reds starters have a 3.18 ERA, second-best in MLB behind the Cards. And while the Pirates' starting pitching was shaky in April with a 4.68 ERA, their starters have posted a 2.88 ERA ever since.

We know the Cardinals and Reds have the goods to keep it up. They both did the awesome starting pitching thing last year, and they've gotten good returns from their starters this year no matter who they've been forced to plug in. Both organizations have a Midas touch when it comes to arms.

The Pirates are less of a sure bet, especially with A.J. Burnett now on the disabled list with a calf injury. Also on the DL are Wandy Rodriguez, Jeanmar Gomez, James McDonald and Jeff Karstens. Until these guys get healthy, Pittsburgh's starting rotation is going to have some water-treading to do.

But at the same time, there's a bright side in Pittsburgh. Jeff Locke has quietly been a stud in 2013, and Francisco Liriano has been a steal with a 2.36 ERA in his seven starts. Gerrit Cole, the No. 1 overall pick in the 2011 draft, debuted this week and showed that he has the goods to be Pittsburgh's first homegrown ace in something like a million years.

Meanwhile in the AL East, strong starting pitching is hardly nonexistent. There are no AL East teams in the top 10 in MLB in starters' ERA, but the Red Sox and Yankees are both in the top 10 of the ERA- ranks, according to FanGraphs. That's essentially the same thing as ERA+ in that it's a park- and league-adjusted version of ERA, except that lower is better with ERA-.

The Red Sox are sixth in those rankings, and the Yankees are 10th. But just behind them are the Pirates at No. 11, and the Cardinals and Reds, not surprisingly, top the charts.

As for the Orioles and Rays, well, they're nowhere near the top of those ERA- rankings.

Baltimore's starting pitching has been about as mediocre as it was last year, and Tampa Bay's starting pitching has been a huge disappointment due largely to the pre-injury struggles of David Price and the inconsistency of Jeremy Hellickson. Dominant early on, Matt Moore has had some overdue bad luck catch up with him in his last few outings.

Why make such a big fuss out of starting pitching?

Mainly because of recent history. Strong starting pitching explains the San Francisco Giants in 2010, the Philadelphia Phillies in 2011 and the Reds and Washington Nationals last year. It also put the Detroit Tigers in the World Series despite an unspectacular regular season.

Point being that, in a day and age when pitchers are the dominant forms of life on the baseball landscape, strong starting pitching has tended to be a defining characteristic of powerhouse teams. The Cardinals and Reds fit the mold better than any of the teams in the AL East, and the Pirates are at least in the discussion. 

The Cardinals and Reds look like virtual locks to make the postseason. The Pirates are less of a lock, but it bodes well for them that the NL East and NL West haven't yet produced any serious contenders for the National League's second wild card spot. If that continues, the Pirates will have a larger margin of error in terms of holding on to it.

It doesn't look like the AL East has a hope of sending three teams to the playoffs. It may house four contenders, but one of the wild cards is sure to come out of the AL West where two of the American League's three best records reside.

I'd bet good money on the AL East still being the deepest overall division in MLB at the end of the season. But a division can't do any better than three teams in the postseason, and the NL Central has a legit chance to accomplish that in 2013.

If it does, baseball's Ancient Rome will have moved camp.

Note: Stats courtesy of Baseball-Reference.com unless otherwise noted.

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