About Diamond GM
Diamond GM is the free MLB payroll, luxury tax, and armchair GM site — the baseball answer to PuckPedia and CapFriendly.
Diamond GM is a fan-built front office for Major League Baseball. Every one of the 30 clubs has a live payroll page, 40-man and 26-man roster, injured list, top-30 prospects, and year-by-year contract breakdown for every player.
What you can do here
- League Hub — all 30 teams ranked by 2026 payroll and luxury tax, with the latest transactions.
- Team pages — full roster, contracts, prospects, and cap situation for every club.
- Player & prospect pages — headshots, stats, service time, draft info, and contract table.
- Armchair GM — pick a team and a year, sign free agents, make trades, set your lineup and rotation, and manage the 40-man.
- Trade simulator — build multi-team trades and check the cap impact instantly.
- Draft tracker & mock draft — live MLB draft board plus a mock-draft mode.
- Publish & discuss — publish your armchair GM roster to the community and let others comment.
Where the data comes from
Rosters, live stats, and IL designations come from the official MLB Stats API. Top prospects come from MLB Pipeline. Contract and payroll data comes from public sources including Spotrac. Everything is refreshed automatically.
Independent fan project
Diamond GM is not affiliated with, endorsed by, or sponsored by Major League Baseball or any MLB club. All team names, logos, and player likenesses are property of their respective owners.