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Buy Low Starting Pitchers

Buy Low Starting Pitchers

Using JA ERA to find buy-low starting pitchers for the second half of the fantasy baseball season

Jon A's avatar
Jon A
Jun 11, 2025
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I’m back for another quick analysis post. I don’t want to belabor the point here. I’m using JA ERA to spot pitchers who have underperformed their skills this year in the ERA column. It’s the same as using SIERA, but we’re using my own ERA indicator just for the branding and ease of it all.

xFIP, SIERA, and the like all predict future ERA better than ERA does itself. That is essentially the whole point of the existence of those stats. Since JA ERA perfectly correlates with SIERA (as shown in the daily notes this morning), we can say the same thing with JA ERA. Read about JA ERA here.

Just to make sure, I did a quick check from 2024. I took each pitchers

→ JA ERA from before June
→ Actual ERA from before June

And then I checked at which one better predicted their ERA from after June. And JA ERA crushed actual ERA. It wasn’t close. Again, this would be the same with SIERA or xFIP. I’m not breaking new ground, I’m just using my own version of the same stat.


Knowing this, we can pick out the guys who have bloated ERAs right now who are the most likely to improve the rest of the way home.

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