As expected statistics continue to make their way into mainstream baseball readership, fans have access to a clearer picture of how well or poorly a player is performing. We can see, for example, that a hitter who is slumping is actually the victim of bad luck, as the balls he hits are squared up but maybe right to a defender. Conversely, we may also discover that a pitcher’s hot streak is in reality a wall-scraping home run here or bloop single there from falling apart.
Yesterday, Andres conducted a thorough investigation into the hitters whose expected statistics signaled bad luck or good fortune in 2019. As the centerpiece of his analysis, Andres examined the disparity between the player’s wOBA and xwOBA. Importantly, xwOBA integrates launch angle, exit velocity, walks, and strikeouts to project how well a player will produce offensively.
I too will employ xwOBA to determine which Yankee pitchers had the best or worst luck last season. A pitcher whose xwOBA exceeds their actual wOBA can be considered lucky, as the batted ball profile would suggest that hitters should have had more success, while a pitcher whose xwOBA falls below their actual wOBA can be considered unlucky. Perhaps their home field was a high run producing environment.
I will also use xFIP to evaluate a pitcher’s luck. Unlike FIP, which measures a pitcher’s performance based on home run rate, walks, and strikeouts, xFIP’s calculation incorporates a projection of a pitcher’s home run rate based on their fly ball rate and the league average home run per fly ball rate (HR/FB%), along with walks and strikeouts. Therefore, a pitcher who surrenders more home runs per fly ball than league average would have an xFIP below their actual FIP, and vice versa.
With that, let’s take a look at the two pitchers who had the most luck fall their way in 2019:
In the case of the righty reliever, xFIP is the smoking gun. While Ottavino’s surrendered wOBA actually exceeds his xwOBA (.276 vs. .271) by a tad, his FIP is almost a whole point lower than his xFIP (3.44 vs. 4.32). Based on his fly ball rate of 41.1% he was expected to surrender a good deal more home runs, however his minuscule HR/FB% of 8.1% falls way below the league average of 15.3%. If he wants to sustain his success in 2020, he needs to cut down on the fly balls, otherwise more may drop for homers than safely find gloves.
The fact that both of Chapman’s expected statistics exceed his actual statistics point to the fact that he was lucky at times in 2019. His xwOBA vs. wOBA was .260 to .242 while his xFIP vs. FIP stood at 2.86 to 2.28. Like Ottavino, Chapman benefitted from the fact that not many of the fly balls hit off him cleared the fence. If he can reduce the launch angle hitters are achieving, perhaps by mixing in the slider even more, I have no doubt he will continue to be a dominant closer in the league.
And now for a look at the pitchers with the worst luck last season.
The first player than came to mind as I brainstormed this article was the lefty veteran. I mean, to rank second in the league in home runs per nine, at almost two, seemed unsustainable for a guy who, the year prior, was excellent for the Yankees. Indeed, Happ did experience some bad luck, indicated by an xFIP below his FIP (4.78 vs. 5.22).
However, a look at his xwOBA suggests that perhaps there is some cause for concern. Because his xwOBA is about the same as his wOBA, this tells me that although he surrendered more home runs per fly ball than league average, this was because batters were hitting the ball with more authority off him rather than due to bad luck.
Happ just was not fooling hitters, which — combined with a middling walk rate and a declining fastball — spelled trouble for the lanky lefty. Look on, ye mighty, but do not despair, for there is hope yet. Happ looked rejuvenated in the shortened spring training, so perhaps Matt Blake has tapped into something left in the tank. I hope we get the chance to see this year.
The fireplug righty was terrific last season, but he might have done even better, as he was the victim of some rotten luck in 2019. His FIP of 3.33 was bloated relative to his 2.69 xFIP, while his xwOBA was ten points lower than his actual wOBA.
The delta in expected and actual FIP stems from his HR/FB% being almost eight percentage points above league average, a disparity we can assume will normalize in the coming season. Additionally, while Kahnle surrendered a launch angle in the single digits, a moderately high exit velocity meant some of those grounders were finding holes. These signs point in the right direction when projecting how Kahnle will perform in 2020.
Note: By both metrics, CC Sabathia was actually the unluckiest pitcher on the staff last year, however, given his retirement I decided to leave him off the list. Still, it bears mentioning that he was plenty effective in his final year, a testament to his longevity.