Baseball's strikeout epidemic is not limited to the free-swingers hell bent on homers. The eight highest monthly strikeout rates in Major League history have occurred in the past eight months of play (with No. 2 all-time having just wrapped up and No. 1 all-time taking place last September), and this doesn't happen unless even the most studious and selective of hitters are striking out at rates at which they are unaccustomed.
Take it from Joe Mauer, as studious and selective as they come.
It's different out there.
"The game has evolved," Mauer said. "This is my 10th year. My first couple years in the league, if you were a sinkerball pitcher, you were a sinkerball pitcher. Now, they throw a sinker, a cutter, a four-seamer. So you're looking for three fastballs instead of one or two."
It's working, and Mauer is the perfect example of how well it's working.
Entering Monday, Mauer had struck out in 19.5 percent of his plate appearances this season, nearly nine percentage points above his career average. And while that data is due, in some measure, to the abnormally cold and cruel April weather conditions the Twins endured, even by Minnesota standards ("I can remember swinging through pitches that I thought were going to break and didn't break because they were wet," he said), it's not all just small-sample stuff. Last year, Mauer struck out at a 13.7-percent clip -- still outstanding, by most people's standards, but nonetheless the highest such full-season mark in Mauer's career.
"I think there are a lot of things that contribute to that," Mauer said.
In Mauer's case, his selectivity can encourage, rather than prevent, some of the strikeouts. He routinely gets himself into deep counts. Since Opening Day 2012, only A.J. Ellis (4.44), Adam Dunn (4.40) and Mike Napoli (4.40) have seen more pitches per plate appearances than Mauer (4.32). And an increasing number of those two-strike counts have led to strike three.
"As you get older, you take a few more chances here and there," Mauer said. "But I think my approach has stayed relatively the same."
An example rests in Mauer's history in 3-0 counts. When he swung at a 3-0 pitch against the Indians' Corey Kluber last Sept. 20, it was his first such swing in more than three years. The fact that he grounded out on that particular pitch only cemented in Mauer's mind the value of staying selective. He has not swung at a 3-0 pitch this season.
"For me, it's about seeing as many different pitches they have," he said. "The more pitches a hitter sees, the more comfortable he feels. So obviously swinging at a first pitch or 3-0, it's probably a guy I've seen before where I know what his stuff is. A lot of guys coming up, you have no idea what they throw until you step in the box. So I try to see as many pitches as I can to have an idea of what they're doing."
Slightly increasing strikeout rates aside, this approach has obviously worked quite well for Mauer over the years. His .322 career batting average is second among active players (trailing only Albert Pujols) with at least 3,000 plate appearances, and his .404 career on-base percentage is fourth (trailing only Todd Helton, Pujols and Lance Berkman).
In Mauer's time in the big leagues, evaluators and fans alike have gained a greater appreciation for on-base percentage and all it entails. The value of a selective hitter like Mauer, who not only creates traffic on the bases but makes opposing pitchers reveal their full arsenal and does his part to push starters out of games more quickly, has been heralded.
"It's about being productive," he said. "That on-base percentage gets overlooked at times, but it gives us a chance to score runs."
But the proliferation of strikeouts, accompanied as they are by a dramatic dip in run production and long balls in recent seasons, makes it clear that there are drawbacks to this approach. Bullpen specialization and the sheer number of hard throwers among relievers has limited the benefits of a starter's early exit. And as Sports Illustrated's Tom Verducci recently pointed out, a decrease in the percentage of first-pitch swings over the past 25 years -- from 33 percent in 1988 to 26 percent in the present day -- has been accompanied by a rise in the overall strikeout percentage, from 14.7 percent to 20.).
More and more hitters have taken a Mauer-like approach to their at-bats, working the count, grinding out the at-bat. The overarching result, though, has been fewer runs, not more. And the rising strikeout rates have not been accompanied by an accordant rise in power production.
Last month, the strikeout rate was 15.29 per game, a total of 5,992 whiffs and called third strikes. The rate has remained relatively stable in the first few days of May.
"As far as this past April, I think the weather probably had a lot to do with it," Mauer said. "But bullpens and teams are deeper with stronger arms and more movement. Just deeper pitching staffs."
And if a guy like Mauer -- a notoriously difficult guy to strike out -- is going down swinging more than ever before, that speaks to the greater trend in the game. Not even Mauer is immune to the game's rising K pace.
Anthony Castrovince is a reporter for MLB.com. Read his columns and follow him on Twitter at @Castrovince.