Looking for a simple way to calculate baseball stats while building a side project

[allentomy]

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Question

Discussion Content

I'm working on a small baseball-related side project, and I needed to calculate stats like ERA, WHIP, OPS, and a few others without having to write every formula from scratch.

I found plenty of explanations about the formulas, but I was looking for something where I could quickly verify my calculations while testing my code.

For anyone who has built sports analytics projects:

• Do you usually implement every formula yourself?
• Do you use an existing library or API?
• How do you validate that your calculations are correct?

For testing, I came across this calculator, which made it easier to compare my outputs with expected values.
I'm mostly interested in learning what workflow other developers use when validating sports statistics.

[Bluenovers]

Few things that helped me with similar stuff:

For the basic stats (ERA, WHIP, OPS) I just wrote the formulas myself, they're like one-liners anyway. Not worth pulling a dependency for those.
If you get into the sabermetric stuff (wOBA, FIP, WAR) that's where pybaseball saved me a ton of time, it pulls straight from FanGraphs/Baseball-Reference so you're not reverse engineering the weightings yourself.
For validation, don't trust a random calculator site as your source of truth. Grab a real stat line from Baseball-Reference (pick a player/season you know), hardcode the expected output, and write a test against it. Way easier to defend later than "some site said so."
That calculator you linked is fine for a quick gut check but I'd swap it out before you rely on it for real testing, no way to verify it's actually right.

TLDR: implement the simple formulas yourself, lean on pybaseball for the complex ones, and validate against Baseball-Reference/FanGraphs numbers not a random tool.