You might have missed this, but offense is up in 2015

Is this summer's offensive surge just a blip, or a sign today's young sluggers are adjusting to a lower strike zone? Getty Images

Zack Greinke is on pace to finish the season with the lowest ERA since Greg Maddux in 1994. Jake Arrieta is in the midst of a Bob Gibson-like run circa 1968. Clayton Kershaw and Chris Sale might log 300 strikeouts. The Cardinals have a staff ERA under 3.00. There have been six no-hitters. Lost in the midst of another season of dominant pitching performances, however, is this little nugget: Offense is up.

I mean, we're not exactly back to steroid-era levels of offense, but after the 2014 season saw the fewest runs per game since 1981 and the lowest major league batting average since 1972, offense is up and that's a good thing, a possible indicator that the trend of lower-scoring games might be reversing. The numbers since 2010, which we can call the "expanded strike zone era":

2010: 4.38 runs per game, .257 average, .728 OPS

2011: 4.28 runs per game, .255 average, .720 OPS

2012: 4.32 runs per game, .255 average, .724 OPS

2013: 4.17 runs per game, .253 average, .714 OPS

2014: 4.07 runs per game, .251 average, .700 OPS

2015: 4.25 runs per game, .255 average, .721 OPS

Home runs are up to 1.01 per game, after dipping to 0.86 per game last year, the lowest mark since 1992, which many would suggest was the last year before the beginning of the steroids era (or at least the year before rising levels of offense kicked in).

A couple of weeks ago, Jon Roegele wrote an interesting article at The Hardball Times, examining reasons why run scoring usually declines in September. Anyway, within this article he had this piece of information:

After three full years elapsed without teams averaging as many as 4.30 runs per game over a single calendar month, major league teams averaged a whopping 4.49 runs per game in the just-completed month of August. This may not sound like a big difference, but you can see from the image above just how unprecedented this is in recent years.

Indeed, teams hit a collective .257/.319/.417 in August. You might think offense always goes up in August because of hotter weather, but that's not the case. In 2014, August produced a lower OPS than April, May, June or July. In 2013, lower than April and May. In 2012, lower than May, June and July.

Anyway, it's now the middle of September and guess what: Offense hasn't declined so far. In fact, it's up even from August. Look at 2015's monthly splits:

April: .250/.315/.390, .705 OPS

May: .253/.314/.398, .712 OPS

June: .255/.314/.399, .713 OPS

July: .255/.316/.403, .719 OPS

August: .257/.319/.417, .736 OPS

September: .259/.326/.423, .750 OPS

So in a month when offense usually declines, offense is up. Teams are averaging 4.75 runs per game. That's almost a 2001 level of offense, when teams averaged 4.78 runs per game -- you know, the year Barry Bonds cracked 73 home runs.

It's also important to note that in Jon's piece, he reports the size of the strike zone as called by umpires is still increasing, up to 478 square inches (through August), three inches larger than last year and a whopping 42 square inches larger than 2010 (almost all of that at the bottom of the strike zone).

What's happening? I would speculate on a couple of things. We have a lot of talented young hitters who have reached the majors in 2015 and the past few years. These guys have grown up in the majors having to deal with the low strike zone and many -- like Mike Trout and Kris Bryant -- have swings tailored to hit low pitches. Aside from that, maybe this is just the natural course of things. Back in spring training, when Jim Caple and I did a story on what baseball can do to boost run scoring, one caution many players raised when we talked with them was to give this time. Don't panic and do anything drastic to mess up the game; give the hitters the chance to make adjustments.

So maybe that's what's happening. Or maybe this is just a blip on the radar. Either way, I'm enjoying the dominant seasons from the likes of Greinke, Arrieta and Kershaw. But it's nice to see more big numbers from the hitters as well.