One thing everyone is missing about the Orioles rotation: ground balls

The 2015-2016 offseason is now mostly complete and the main storylines of the 2016 Orioles are in place. Watch as the Zach Britton and Darren O'Day methodically dominate the late innings. Hear the crack of the bat and the roar of the crowd as Pedro Alvarez crushes a high fastball onto Eutaw Street. And feel the breeze rush past your face when Chris Davis swings through a breaking ball in the dirt.

That's it. Case closed. The narratives of the 2016 Orioles have been written.

Or have they?

There’s one item that almost no one is paying attention to. Lost in the offseason/preseason discussions is how the Orioles rotation recorded more ground balls per batter faced in 2015 than in any of the five years prior:

Every starter save Wei-Yin Chen pitched in:

Ubaldo Jimenez led the charge. Due to some offseason adjustments that tightened up his release point, Jimenez cut his 2014 walk rate by a whopping 5.3 percentage points. Fewer walks means more balls in play, but thankfully most of those balls scooted across the lush green infield grass. Despite a jump in BABIP from .298 to .309, Jimenez was a league-average pitcher by ERA- and better-than-average by FIP- and xFIP-.

Noted flyball pitcher Chris Tillman hopped aboard the train, debuting a sinker to mild success in the second half of the year. The pitch probably isn’t quite where he wants it to be, but it surely boosted his groundball rate.

However, it wasn’t only his sinker that factored in. Tillman aimed all his pitches lower than in the past:

I’m surprised that Kevin Gausman joined the crowd, because he generated some interest last year with an elevated fastball in June. But that month was just a blip. During the season’s other five months his fastball landed, on average, below the center of the strike zone:

Let’s pause for a moment. Why should you even care how many ground balls the staff gets?

There are a few main reasons:

• League-wide, the average wOBA on a ground ball is a measly .220.
• The Orioles are projected to have the best infield defense in the game by Defensive Runs Saved (DRS). Ground balls involve mostly infielders, thus playing to the team's strength.
• Oriole Park at Camden Yards is a notable hitters’ park, third-best in 2015 according to ESPN’s Park Factors. The biggest chunk of that inflation occurs for home runs. Ground balls generally do not become home runs and thus avoid the park's main weakness.

Each holdover in the rotation saw one pitch work particularly well, but Jimenez's slider was the king of groundball improvements. Compared to 2014 it generated 21.31 more ground balls per ball in play. In second place was Chris Tillman's cutter at +19.79 GB/BIP. Kevin Gausman's splitter got 10.63 more GB/BIP, and even Miguel Gonzalez's fastball got into the act at +7.18 GB/BIP.

But it's not just the pitchers you know and love. The Orioles made three offseason pitching acqusitions, and they all bring an above-average groundball rate to the table:

• In 2015 Odrisamer Despaigne induced 22% more ground balls per batter faced than the average starter.
• Yovani Gallardo induced 18% more GB/BF.
• Vance Worley induced 15% more GB/BF.

The signings of these pitchers, combined with the staff’s season-to-season change last year, signals a clear strategy. If it were one or the other, maybe you could write it off. But there's enough smoke here that there's bound to be some fire.

It’s a strategy that is long overdue. OPACY has been a hitter’s park for awhile now and Manny Machado and J.J Hardy have anchored the infield defense for the past several years (Manny’s injuries notwithstanding). Jonathan Schoop had a great defensive year in 2014, proving at least some talent is there, and even Ryan Flaherty can pick it. The use of infield shifts will further help the defense.

So I'm happy to see the team shifting (pun definitely intended) away from its flyball-centric mentality. In 2016, watch and see how well the starting rotation executes on this new worm-burning direction.

Anything to keep the ball away from Mark Trumbo in right field.

All data from FanGraphs except where noted as being from BrooksBaseball or ACTA Sports.