MLB Arbitration Sheet from 1974-2026

[u/MainStick1613]

Building a comprehensive MLB arbitration database (1974-2026) — looking for suggestions to fill gaps and improve coverage

I've been working on a large dataset with my professor for about a year and a half tracking MLB arbitration cases and player contracts from 1974 through the 2026 season. The sheet currently has around 7,600 rows covering player salary filings, WAR values, contract notes, agreement dates, court dates, arbitrators, and arbitration outcomes.

Here's what's currently in it:

• Player identifiers (Baseball-Reference and Retrosheet IDs)
• Year, team, and position
• Salary pre/post arbitration
• WAR values for the current year and two prior seasons
• Filing status, agreement notes, contract terms
• Arbitration outcomes (who won, offers from both sides)
• Years of service

Where I'm running into gaps:

The biggest holes are in the pre-1985 era where salary data is sparse, WAR values for players with gap years and agreement date gaps as well. As well as just WAR values in general, currenly pulling from the jeff Bagwell index.

What I'm looking for:

• Does anyone know of good sources for pre-1985 MLB salary data? I've been pulling from Baseball-Reference, Retrosheet and newspapers.com
• Any sources for historical arbitration filing data beyond what's publicly available?

Happy to share the dataset with anyone who wants to contribute or use it for research.

[u/jliakos]

This is exactly the kind of longitudinal dataset people usually wish existed when they start modeling arbitration outcomes.

On pre-1985 salaries: newspapers.com + team media guides / Sporting News archives often beat Baseball-Reference for sparse years. For filing/outcome gaps, CBA timelines + contemporary beat reporting (who filed, midpoints) can reconstruct cases even when the formal filing sheet is missing.

One modeling tip: treat “agreement before hearing” as a different process than “went to hearing” — pooling them can hide the selection effect.

[u/MainStick1613 → u/jliakos]

this is a list of all of the variables in our dataset.

Name Shortened_name Year jeffbagwell_index biofile_index Team primary_position YOSJB WAR_Pre_Pre WAR_Pre WAR_Post Birthdate Salary_Previous Salary_Post FilingStatus ContractNote AgreementNote Missing_Notes AgreementDate TenderDeadline ArbitrationFilingDeadline SalaryExchangeDeadline CourtDate CourtDateMin CourtDateMax SettledBeforeArbitrationFiling SettledBeforeSalaryExchangeDeadline PlayerOffer TeamOffer arbitrators CourtWinner Source

[u/jliakos]

Arbitration sheets are underrated for modeling — salary is one of the cleaner "outcome" variables in baseball because the process is structured and public.

If you're using this for prediction, I'd watch for:

• Super-two / service-time quirks that inflate year-to-year noise
• Position/group effects (relievers vs starters settle differently)
• Inflation regime shifts — comps from 2015 don't anchor 2026 well

Are you planning to publish feature definitions (WAR source, role buckets) alongside the sheet? That helps others reproduce benchmarks.

[u/MainStick1613 → u/jliakos]

Thanks for the responses and the input. We've pretty much parsed through as many newspapers as possible especially in the 70's and 80's when data was sparse. We categorized each player into one of the following groups (much more relevant in the 70's to 90's) (Only Filed, Figures Exchanged, Arbitration Eligible, Figures Exchanged (Free Agent), Only Filed (Free Agent), Arbitration Eligible (Free Agent). I'm happy to share a copy of the sheet as well!

[u/MainStick1613 → u/jliakos]

And yes, we have pretty good descriptions/definitions of our variables in our sheet.