It's not just that offense has declined -- though it has. It's that the shape of offense in the big leagues has changed pretty drastically in the past decade-plus.
First, a little context. Entering Thursday, Major League teams were averaging 4.2 runs per game in 2013. That's down slightly from the previous three years (all between 4.28 and 4.38) and down significantly from the 15 or so years before that.
Overall, the past four years are right in line, scoring-wise, with most of the time between 1973 and 1992. Those may seem like arbitrary endpoints, but they're not. In 1973, baseball introduced the designated hitter. In 1993, the Majors expanded for the first time in 16 years.
So let's not, just yet, turn this new era into a recreation of the offense-starved late 1960s. It's a change from what we'd gotten used to, but it's not historically low-scoring.
But, again, it's certainly noteworthy, after the offensive eruption for much of the '90s and 2000s. And while the knee-jerk answer is "drug testing," it's not that simple.
Baseball analyst Joe Sheehan ran some numbers recently, and came to the conclusion that while home runs are down (though, again, only slightly), the raw totals don't tell the whole story. There are in fact fewer home runs, but it's mostly because there are fewer balls in play, period. Home runs are down significantly; home runs as a percentage of balls put in play are down only slightly.
So while drug testing may well be a factor, it's hard to argue that it's the only factor. If players were becoming less muscular, benefiting less from the purported effects of illegal performance-enhancing drugs, the ball would be flying less far on contact.
But instead, when big league hitters hit the ball, they hit it out of the park very nearly as often as they did during what's become known as the "steroid era." They're just not hitting it as often.
Which gets back to the original point. What we've seen the past four years, more than anything, is the rise of the strikeout. Whether it's a matter of power arms, a change in the culture of hitting, bullpen specialization or all of the above, hitters are striking out more and doing almost everything else less.
From 1946 through 1994, there wasn't a single season in which more than 15.9 percent of Major League plate appearances ended in strikeouts. From 1995 through 2008, it was higher than 16 percent every year but never reached 18 percent. In 2012 and 2013, it's 19.8 percent. That's an enormous increase.
"Swings are getting longer to hit more home runs," said Mets pitcher LaTroy Hawkins, who came up in the offense-happy mid-1990s. "You're going to get paid hitting .220, with 25-30 [homers]. You're going to get paid, as opposed to a guy hitting .300 with two home runs and 41 RBIs. So guys are sacrificing the batting average for more power."
That's surely one factor, but it's not the only one. There is, self-evidently, a rise in the number of big-time, power arms in the Major Leagues. It's a great time to be a fan of dominant pitchers, because there are a lot of them.
To name just one piece of evidence, take a look at the average fastball velocity in the Major Leagues. According to Fangraphs.com, it's climbing. From 2002 (the first year the data are available) through 2008, the highest average velocity was 90.7 mph. Since 2011, it's been 91.5 or higher.
"I see a lot of big arms, I know that," said Rockies manager Walt Weiss, who played from 1987-2000. "I see a lot of guys in the mid- to upper-90s that I didn't see before."
And then there's specialization. It hasn't even been 30 years since Earl Weaver wrote "10 pitchers are too many" in the essential "Weaver On Strategy." If you were to carry only 10 pitchers in 2013, it would be considered revolutionary. In fact, as of Thursday afternoon, only one team in the Majors was carrying even 11. Nearly a third had 13 -- more than half the roster.
That obviously, necessarily, means fewer hit-only players, those pure pinch-hitters like John Vander Wal, so offensively challenged players must hit for themselves more often. But it also means more right-on-right and left-on-left matchups in the middle innings, as managers can exploit platoon advantages with their pitchers earlier and earlier.
Those hard-throwing kids coming up? Even the ones with limited secondary stuff can be put in a middle-relief role and turned loose on same-side hitters, often with devastating results.
"Jason Isringhausen and I last year played in Anaheim, and we were amazed how many guys came in just in the American League West and threw 97 to 100," Hawkins said. "We saw it almost every night. We were saying, 'Where do they find these kids?' ... You can tell teams are definitely going to power arms, and it kind of correlates with guys striking out more."
More power pitchers, more specialization, more aggressive swings and drug testing. They've all come into play in recent seasons, and it adds up to a different game than we got used to seeing over the previous 15 years.