Starting Pitcher Auto Out Percentage Surgers

Auto Out% (AO%) surgers…huh?! Yeah, I just made it up. But you know what this metric is because my colleagues have written articles about it. It’s simply strikeouts plus infield flies as a percentage of batters faced. These are essentially automatic outs, hence the name Auto Out%. We know that for pitchers, strikeouts are the best plate appearance result because it’s an almost guaranteed out. But infield fly balls aren’t too far behind in terms of out conversion. Yet, we focus far more on a pitcher’s strikeout rate than his popup rate, which is often completely ignored. Combining them gives us even better information than focusing on just one of the pair. So let’s find out which starting pitchers have improved their AO% the most versus 2017.

No one should be surprised to find Gerrit Cole far and away the leader here. Not only does he sit comfortably atop the surge leaderboard, but he actually ranks third among all qualified pitchers in AO% this year. We’re all well aware of the dramatic spike in his strikeout rate, but did you also know that his pop-ups, as a percentage of batters faced, have jumped from 2.7% to 3.1% as well? The only reason it’s not higher is because so many more of his plate appearances have ended in a strike out, so batters are finding it far more difficult to put the ball in play.

I still remain skeptical of Mike Foltynewicz’s strikeout rate spike given his pedestrian SwStk%, but those strikeouts did happen, and they have been paired with a career best IFFB%. The additional pop-ups should help him post a career low BABIP, but he’s still in no way deserving of a .256 mark. He has clearly taken his first step toward a breakout, but he’s a prime sell high candidate.

Patrick Corbin isn’t inducing any more pop-ups, so this spike is all strikeout rate driven. That surge is backed by a SwStk% that has skyrocketed into the mid-teens, as his already elite slider sports its best SwStk% mark yet. A loss in fastball velocity since early in the season hasn’t slowed him down.

Remember when we thought in 2014 that Justin Verlander’s decline had come and all that mileage was finally catching up to him? Oops. He’s now sitting with the highest strikeout rate of his career and second highest IFFB%. Oh, and since his fly ball rate is the highest its ever been, by far, then that higher IFFB% translates into even more pop-ups. In fact, his 7.7% popout rate is easily the best of his career. With two Astros pitchers on this list, clearly they are doing something right.

Derek Holland represents the first true surprise on this list. Did you even realize he was still pitching?! He’s actually still just 31 years old, but injuries and poor performance made most of us forget about his existence. All of a sudden, his strikeout rate sits at a career high, as does his IFFB%. Surely the move to the National League for the first time has helped on both fronts. But his fastball, which has been terrible for a while now, is sporting its highest SwStk% since 2011, and his cure is at its highest mark. It was seemingly just a matter of health for Holland.

We’ve been waiting for years for Kyle Gibson to break out, and this year the results have suggested that this is finally it. SIERA would disagree, of course, but a huge strikeout rate jump above 20% for the first time is a pretty clear point of excitement. It’s pretty crazy that he always featured an excellent trio of non-fastballs which have all generated SwStk% marks in the mid-teen to 20% range over his career, yet his strikeout rate always languished. That’s because his fastball has been terrible at inducing whiffs, which it still is now, but the non-fastballs have made up for it for the first time. His slider, changeup, and curve ball have all generated career best SwStk% marks. If only he had any semblance of a whiff-inducing fastball, he’d be a stud!

On the heels of a velocity decline and skills erosion, I thought Cole Hamels was done. And while his ERA suggests that might actually be the case, his strikeout rate has fully rebounded as if last season never happened. Unfortunately, his velocity is down another tick and at age 34, it might not come back. Still, he should maintain some AL-Only value the rest of the way, but I wouldn’t really care to own him in a shallow mixed league.