The Oakland Athletics entered Monday up 2 1/2 games over the Seattle Mariners for the second wild-card spot in the American League. A fair amount of the A's success can be tied to closer Blake Treinen's ascent, which has resulted in a 0.95 ERA and 4.17 strikeout-to-walk ratio.

Treinen tends to pitch late at night, making it difficult for the East Coast crowd to appreciate his year. Even those who do watch him often might not have noticed that he's leading the league in an important category: Coercing batters to expand their strike zones.

According to Baseball Prospectus, Treinen has baited the opposition into swinging at 43 percent of his pitches thrown outside of the strike zone. That's the highest clip in baseball, minimum 500 pitches. A wider look reveals that Treinen's talent for making 'em chase is near-historical. In the PITCHf/x era (2008 onward), only four other pitchers have recorded a higher fish rate for a single season: Edward Mujica, Sean Doolittle, Koji Uehara, and Mark Melancon.

Treinen isn't the only pitcher who has found success by throwing outside of the box. Last week, Jared Diamond of the Wall Street Journal highlighted how the Arizona Diamondbacks have become fond of a particular type of pitcher -- one who avoids the strike zone. Here's a takeaway quote from pitching coach Mike Butcher:

"Guys are trying to launch and hit more fly balls. They're trying to beat shifts," Diamondbacks pitching coach Mike Butcher said. "Deceptive pitches are an equalizer to all those things."

For as much as Treinen relies upon batters expanding the zone, it's unclear whether he's following Greg Maddux's old advice ("make the strikes look like balls and the balls look like strikes") or simply benefiting from nasty stuff. Both his primary offerings, a turbo sinker and a wipeout slider, dart toward (and often beyond) the fringes of the zone:

Shy of committing to not-swinging beforehand or batting in slow motion, there's not much the opposition can do against those pitches. As such, it doesn't matter whether Treinen's approach is the byproduct of a gameplan, talent, or some combination thereof. What matters is Treinen has found a recipe for success that has made him one of the top relievers in baseball.