Data sources and attribution
What our numbers are built on, and what they are not built on.
Retrosheet
Our historical game data, including starting lineups, batting orders, fielding positions, starting pitchers and player handedness, comes from Retrosheet. We currently use the 2023, 2024 and 2025 seasons. Retrosheet requires the following statement to appear prominently:
The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at "www.retrosheet.org".
The statement also appears in the footer of every page. Retrosheet's full notice, as published on its website, reads:
Recipients of Retrosheet data are free to make any desired use of
the information, including (but not limited to) selling it,
giving it away, or producing a commercial product based upon the
data. Retrosheet has one requirement for any such transfer of
data or product development, which is that the following
statement must appear prominently:
The information used here was obtained free of
charge from and is copyrighted by Retrosheet. Interested
parties may contact Retrosheet at "www.retrosheet.org".
Retrosheet makes no guarantees of accuracy for the information
that is supplied. Much effort is expended to make our website
as correct as possible, but Retrosheet shall not be held
responsible for any consequences arising from the use of the
material presented here. All information is subject to corrections
as additional data are received. We are grateful to anyone who
discovers discrepancies and we appreciate learning of the details.
Copied from Retrosheet's notice on October 28, 2026.
Retrosheet is not responsible for our projections. Any errors in how we process or interpret the data are ours.
Current-season data
Retrosheet publishes completed seasons, so it cannot tell us about today's games. Live projections will need a source of current schedules, rosters and posted lineups. We have not chosen that source yet. We will name it on this page, with any attribution it requires, before we use it.
What we do not use
- We do not collect data from MLB's own websites, apps or data feeds. Our injured list guide cites MLB's public glossary and MiLB.com's transaction glossary as sources for rule explanations; no data is taken from them.
- We do not copy lineups, projections, injury notes or other content from other lineup or statistics sites.
- We do not use league or team logos, photos or other marks.
What we publish
We publish our own derived figures, such as start probabilities, projected batting orders and grading results, rather than copies of source data tables. Facts drawn from Retrosheet data on our guide pages are labelled as our own calculations from Retrosheet data.
Found an error?
If you spot a mistake, please tell us. If it comes from the source data, we will also pass it on to the source where appropriate.