Jake Arrieta is a tough customer to deal with when he has his swing-and-miss stuff going on the mound. But even when batters do make contact, often times the results aren’t much better.
Arrieta’s 25.2 percent soft contact rate and 56.7 percent ground ball percentage both rank ranks seventh in the majors. That combined ability to avoid well-struck balls and keep them on the ground is yielding a uniquely impressive volume of recorded outs via the groundout.
In his first eight starts, Arrieta has induced 76 ground balls – 72 of which have been converted into outs. That means a ridiculous 94.7 percent of ground balls off the bats of opposing hitters have resulted in outs.
Turning nearly 9 of 10 ground balls into outs is a team effort that is in part a testament to Arrieta’s ability to work down in the zone with his sinker (7.7 runs saved is baseball’s best number, per PITCHf/x’s pitch type value) … and a reliable defense behind him.
Indeed, this trend isn’t exclusive to Arrieta. It turns out that the Cubs’ five starters are collectively good at getting ground balls, and seeing those ground balls converted into outs (stats through Arrieta’s last start):
The Cubs’ combination of having pitchers whose stuff is conducive to getting ground balls and an infield defense that is steady is a perfect storm, which has aided in the pitching staff’s strong start.
Arrieta, Lester, and Hendricks have had the good fortune/skill of having a vast majority of their ground balls turn into outs. Lackey and Hammel at least hover around the league median in this regard. For what it’s worth, it helps that Arrieta and Hendricks both rank in the top 10 in ground ball rate and total ground balls induced.
And yet, this isn’t strictly limited to the Cubs’ starting five, either:
Coming into Friday’s series against the Pirates, the Cubs owned a league-best 51 percent ground ball rate, induced the 15th most ground balls, turned in the 10th most ground outs, and converted the ground balls into outs at the second best rate in baseball.
Clearly, reliable defense has gone hand-in-hand with the team’s ability to turn ground balls into outs, especially up the middle.
Second baseman Ben Zobrist has made 100 percent of plays deemed as certain/almost certain by Inside Edge Fielding, while Addison Russell has made 97.8 percent of those plays. And while Kris Bryant has not played enough innings at third base to qualify for the leaderboard, he has made 97.2 percent of those types of plays – which is a slight bump from 94.8 percent in 2015.
Things could get even better if Zobrist can convert on a higher rate of “likely” plays, which currently sits at a small-sample 33.3 percent. Last year, he converted 80 percent of those plays at second base and 68.6 percent over the course of his career.
Strikeouts are great, and ground balls are great. But success requires a bit more. So far, so good for the Cubs’ pitchers and infielders.