Ian Krol - One Hit Wonder or Diamond in the Rough?

N. Markakis and I. Krol / By Staff Sgt. Jason Duhr [Public domain],
via Wikimedia Commons

When the Braves acquired left-hander Ian Krol from the Detroit Tigers last winter, fans were not that impressed. The player he was traded for, Cameron Maybin, had been a fan favorite during the 2015 season and many felt that he was worth more than a lefty reliever with less-than-studly totals in the majors. Maybin's value was at its highest around the trade deadline, when I wondered at my old About.com gig if a trade made sense.

But a trade didn't happen until November. As Demetrius Bell of Talking Chop wrote, "The Braves could have (and arguably should have) gotten more with a Maybin trade at that point, since the return for Atlanta here and now isn't exactly the most inspiring." He's not wrong. In addition to Krol, the Braves got Gabe Speier, a left-handed bullpen piece in A-ball. The latter would soon be traded to the Diamondbacks in the Dansby Swanson trade.

That left Krol, who was being traded to his fourth organization since 2012. Over the previous three seasons, he had appeared in 110 games in the majors with a 4.91 ERA and equally underwhelming 5.03 FIP. He gave up a ridiculous sum of homeruns (15 in 88 ING, 1.5 HR/9) and while righties owned him, his marks against lefty weren't stout enough to suggest he was a left-hand specialist. Hardly the kind of return some had dreamed of for Maybin.

Things wouldn't look much better that spring. In seven games, Krol pitched 5.2 innings and allowed eight runs. he walked four compared to three strikeouts and despite not having a lot of competition from lefthanders, the Braves chose to demote Krol and bring back Eric O'Flaherty, who had just failed to make the Pirates' roster.

Krol headed to Gwinnett, where he was up-and-down. However, one thing he was doing a good job of was getting strikeouts. In 12.1 innings, he struck out 14 compared to six walks. The Braves and Krol were beginning to tweak the lefty's pitch selection and it would pay off big for both.

Before 2015, Krol worked off a four-seamer, a curve, and a changeup. The problem was he was basically living off his fastball, which has mid-90's velocity and good natural sink to it. It's a plus pitch, but without the secondary offerings, his fastball is wasted as he tries to survive at-bats rather than dominate them. While with the Tigers in 2015, he began to tinker with a two-seam sinking fastball and a hard slider. The sinker got a good deal of whiffs - especially when you compare the pitch to others' sinkers. However, it was his slider that became difficult to handle. Rather than a sweeping slider, it's thrown very hard and with some 12-6 movement to it. 18% of the time he threw the pitch in 2015, it was swung-on-and-missed.

Yet, Krol's results still looked miserable. Part of the problem was that Krol was throwing too many pitches. In 2015, he relied on his fourseamer 49% of the time, his slider 22% of the time, the sinker 12% of the time, and then used his curve and change-up a combined 17% of the time. Relievers rarely need five pitches, especially ones who throw a 95 mph fastball. Further, he wasn't throwing either the curve or change-up for strikes, further limiting their effectiveness. The Braves pushed Krol to rarely throw his curve and changeup and, instead, throw his sinker and slider more.

Once Krol got back to the majors in May, it was pretty clear that he wasn't the same guy who forced the Braves to go shopping for a lefthander at the end of spring training. Consider this: In 2013, Krol had multiple strikeout games six times. In 2014, he did it seven times. The next season, he did it five times. In May of 2016, despite being called up on the tenth, Krol had multiple-K games six times. He would finish with 14 over the season. He was simply a more dominant pitcher and that was in no small part to pitch selection.

The Braves also continued Detroit's work with Krol's release point. Compare these two videos. While they aren't exact copies in angle, it gives you an idea of a tweak that began with the Tigers that also shows up in the numbers.





In the first video, which is much better for looking at pitching mechanics, we see footage of Krol in 2013. That season, he had a vertical release point of about 5.8. Keep in mind that vertical release points can change with different pitches. Also, it's worth remembering that Krol is listed at 6'1". With that in mind, his average vertical release point last year was a shade over six feet - closer to 6.2 on his fastballs. You may notice I used decimal points for release point rather than a traditional feet/inches display. This is because PITCHf/x does it by decimals so 6.2 is actually a bit lower than 6'2" because 12 inches is squeezed into 10 decimal points. For more on release points, check out this Five-Thirty-Eight article on a former Cy Young Award winner.

The results speak for themselves. In 2016, Krol struck out 25.8% of batters, a 6% rise in strikeouts. Conversely, he walked just 6%, a drop from its previous level of 9.5%. His biggest gains came in batted ball, though. He went from a 41.2% groundball rate to a 52% rate in 2016. That's a significant change. Further, the sinker and slider have finally neutralized righties for Krol. Before 2016, Krol had a 6.22 FIP against righties and a 2.3 HR/9. In 2016, he nearly cut that FIP in half (3.12) and lowered his HR/9 against them to a far more workable 0.93 HR/9.

Can Krol repeat this in 2017? Well, the Braves did change pitching coaches and Krol's success reminds me what former pitching coach Roger McDowell stressed so frequently (sinkers and grounders). That said, much of the work began with the Tigers in 2015 and was only refined and tweaked by the Braves last year. That gives me hope that Krol will continue to pitch well into next season.