Which Pittsburgh Pirates pitchers suffered from bad luck on their offerings during the 2023 season?
There are so many ways to evaluate and analyze MLB players in today’s game. With the implementation of Statcast in 2015, and subsequently Baseball Savant as a database for Statcast, every pitch and every batted ball, along with their metrics, defensive positioning, and everything in between has been logged since 2015. Many stats, such as xwOBA, or expected weighted on base average, have been created by using these metrics. Since these stats such as xwOBA have a predictive factor to them, it’s been easier to identify luck in baseball.
What I want to use xwOBA for today is looking at the outcomes of pitches thrown by Pittsburgh Pirates pitchers, and examining who was the unluckiest in 2023. The lower the expected wOBA, and the higher the actual wOBA, the more unlucky the Pirates’ pitcher’s offering was.
Before we get into our first players, let’s give a brief rundown of what these stats are. wOBA, or weighted on-base average, is what many consider a better alternative to OPS. OPS weighs a hit and the walk as the same thing. It also solves the issue of those who don’t agree that a double is twice as valuable as a single. Each walk, HBP, single, double, triple, and home run is scaled differently. xwOBA, or expected weighted on-base average uses exit velocity, launch angle, sprint speed, to estimate what the wOBA of a player or outcome should be with these factors taken into account.