Astros: Early Indicators- What Astros Batters Will Get Better and Not
I have gone into a deep data dive today for one purpose-
Which Players are Likely to get HOT from their early starts.
To do this we are going to look primarily at the players and the teams wOBA vs. xwOBA gaps. Warning this may get very data wonky. I will do my best to explain what the numbers MEAN.
Here is the MLB.com explanation of wOBA and xwOBA
Let's start by defining what we have called the wOBA gap here. My definition is the expected wOBA (aka xwOBA) minus the actual wOBA. IF a batter's or a team's of hitters xwOBA is greater than their wOBA then they have been unlucky, and their results SHOULD get better.
Average wOBA/ xwOBA was 0.310 in 2022 and so far in 2023 it is 0.321.
Let's look at the data from early 2022 in the first 18 games and how those players finished the season.
Disclaimer: 18 games is too small of a sample size BUT this is where we are in 2023. I will update probably 30-40 games in. The xwOBA stats do generally better than you would think they would.
Pick any player and study the "Gap" column. I will use Tucker as the example. Tucker was off to a terrible start in 2022. After 18 games his wOBA was a poor 0.275 but his xwOBA was an all-star level 0.372. I kept pointing to that xwOBA number to say it would get better. Tucker's wOBA gap was an extreme 0.097. Which did a better job of predicting his final 0.348 wOBA? The xwOBA.
This predictive nature is NOT always true. We are dealing with statistics here. Of the 12 players listed where the difference was significant, xwOBA did a better job predicting the future 18 games into the season for seven of the individual players and the team. wOBA was a better predictor for four players.
Now look again at the "Gap" column. All by TWO players had positive wOBA gaps meaning they SHOULD get better. The TEAM had a 0.032 wOBA gap. The early xwOBA of 0.310 was far more predictive of the final 0.324 wOBA than the performance to that point. THIS is why Astros fans did NOT have to freak out about the batting in 2022. There was data showing it WOULD get better.
The Astros batters ended up at the same 0.324 wOBA and xwOBA last year. Other teams had season gaps.
You have to know what we are going to do next. Let's look at the wOBA gaps for the 2023 season.
Remember, I said league average wOBA so far is 0.321. Notice there is NO significant team wOBA gap and it is below league average. As a team, one should not ASSUME that the current players will be better. Of course, it WILL get better with Brantley and Altuve assuming no other Astros get seriously injured.
What individual players can we expect to be better this season than they have been so far? (Group on left)
What individual players can we expect to be worse? (Group on right)
Wait, Tucker should be better than he has been? That is what the wOBA gap method would conclude. Hard to believe. Tucker for MVP!
Meyers can be worse? That is what the analysis says.
More problematic may be who isn't on either list.
- Hensley will maybe see a small positive bump- he needs it
- Abreu will maybe see an even smaller positive bump- let's hope he follows his career trend of getting hot in May.
- The model says Diaz will essentially stay where he is- he needs more PA to be definitive
- Pena might actually get a little worse? Let's hope not.
Let me know what questions this sparks in your mind.
P.S. There is a non-Astros player I feel compelled to comment upon because of his fans JUST WON'T LET HIM GO - Yuli Gurriel.
Here is a fact for the #YuliTreatment crowd. Something for you to consider when screaming the Astros should have kept Yuli.
There are 310 players in the MLB with more than 30 PA.
Yuli Gurriel is 306 out of 310 in xwOBA at 0.201. Find the Astros hitter in the table above with a 0.201 xwOBA- you won't.
His wOBA gap shows it could get much much worse for Yuli. No, fans, I don't hate Yuli. If I was his friend, I would have told him it was time to enjoy being the Cuban Legend he is.