The two words that probably best describes Chicago Cubs’ starter Jon Lester are reliably consistent. Going into his 13th season, that aspect really hasn’t changed, but there are some noticeable differences to Lester so far in 2018. Although ERA and winning percentage aren’t really held in high regard given all the advanced metrics available that tell us more of the story, for Cy Young candidates those are two metrics still used heavily. Lester finished top four in the Cy Young voting on three separate occasions and was a focal point of three World Series winning rotations, so he’s no stranger to hardware.
However, that is one difference between previous seasons and 2018; he’s almost certainly not going to finish in the Cy Young race given the current pace. I say that because when looking at his numbers, metrics and charts all I see is someone who’s getting extremely lucky in terms of outcomes.
He has the league’s best winning percentage with .846 and seventh best ERA at 2.25, but despite those numbers his ERA to FIP difference of 1.90 is the worst differential in the league. His 4.15 FIP is certainly higher than you’d expect but so is his xFIP with 4.51, both the highest they’ve been since his sophomore season in 2007. His high xFIP tells us that his 10.2 percent home run per flyball rate should be higher than it is given all the factors involved. That makes sense that he had a home run per flyball rate of 15.8 percent last year and 12.2 percent in 2016. Add in the fact that his flyball rate of 38.2 percent is the highest since 2007 and his hard contact rate of 34.7 percent is a career high. Realistically once those fly balls are hit harder than they currently are, it will translate into a ton of home runs.
FanGraphs touched on this same topic a few weeks ago, diving into how a lot of the success up to this point is because of Lester’s effective curveball and changeup. But I wanted to take it a few steps further, because I don’t buy at all based on what I’ve seen that his curve and changeup should be where they currently are.
The most glaring thing I’ve seen is the location on the pitches and particularly the change in location over the past three seasons. First his curveball this season is almost exclusively thrown inside of the strikezone and quite high up in zone too, compared to previous seasons were most were located outside of the zone.
His changeup isn’t much different. In previous seasons he would locate it on the edge or out of the strike zone, but this year almost all the pitches are being thrown in the zone. Plus they’re just about as high as where the upper reaches of his curve are.
Location is a big deal but that’s only one large piece of the pie; we also have to look at things like pitch usage and whiff percentage. The usage on the curveball and changeup has slightly increased the past three seasons; meanwhile, the whiff percentage on both pitches has dropped significantly.
Between the location of the pitches and the usage and whiff percentage, it’s only a matter of time before those groundouts and fly outs he’s getting on the pitches turn into singles and extra base hits.
Another huge red flag this season for Lester is his regression in strikeouts and slight increase in walks. Last year he struck out 8.97 batters per nine innings whereas this year it’s dropped to 7.11. He’s also increased his walks per nine from 2.99 last year to 3.15 this season.
This is espeically important for someone like Lester who’s use to striking out well over eight batters per nine innings and also has experienced some regression in velocity since his first couple of seasons because when the strikeouts drop like that and then the walk rate increases, more balls are being put in play and often times with runners on base given the walks, so this only increases the chances that Lester gives up more hits and more runs.
Additionally, when more balls are put into play it increases the pressure on the defense as they can only make plays within their reach and eventually those balls that are playable to the defense will instead be hit towards gaps and spaces between the defense.
Which segues into another large contributor to Lester’s current success, the Cubs’ defense. They have the fourth highest defensive efficiency in the league this year and third in total zone total fielding runs above average, which combines the number of runs above or below average the team was worth based on the number of plays made.
When you average that out over a full season, they have the highest in the league as of now. So without a doubt, the Cubs have one of if not the best defense in the league, so this would explain Lester’s career low batting average on balls in play of .246. As the season progresses we’ll get an even better idea of how much of Lester’s success is due to the having one of the league’s best defenses behind him.
Given all of these factors in comprising the seasonal outcomes of a pitcher, Lester seems to be off on almost every single one. So while yes, he’s been relatively successful up to July, there’s no doubt that before we get much deeper into the season those numbers will flip. With all the chaos of baseball, there’s no way Lester can keep up the current success. After all luck eventually runs out, it’s just a matter of time.