Posterior release notes are written for users: what improved, what it changes in the daily MLB workflow, and how the product is becoming more useful. We avoid raw commit notes and implementation recipes so the product stays transparent without giving away the work that makes it different.
Latest
P-26.06.001
June 2, 2026
Cadence
Receipt
Every meaningful release
Format
P-YY.MM.NNN
Posterior release ID
01 / Latest
P-26.06.001 · Model Quality
Release receipts for model quality
Posterior added a stricter release receipt for probability updates. Candidate improvements now have to prove they improve recent resolved output before they are promoted.
What changed for users
More disciplined model updates instead of short-window chasing.
Clearer separation between live product output and research candidates.
Better protection against updates that look good briefly but fade on a larger sample.
Release notes
New internal release gate for Brier score, log loss, market-reference coverage, and signal coverage.
Cleaner release language around what changed and what it means for daily users.
A repeatable report that helps decide whether a model candidate stays in shadow review or becomes production output.
02 / Archive
Backfilled product history.
P-26.05.008 · Personalization
Team-first slate views
The team view was tightened so a selected club can drive the visible slate, desk context, and follow-up reading more naturally.
What changed for users
Favorite-team users get less league-wide noise.
Team pages feel closer to a daily desk than a generic standings page.
The product better supports users who follow one club closely.
Release notes
Improved My Team framing on the daily MLB view.
Clearer links from the daily slate into team desks.
Better handling for nights when the model does not find a team-specific entry worth highlighting.
P-26.05.007 · Reliability
Safer slate publication checks
Posterior expanded the checks around lock windows so daily entries are published only when the inputs are timely enough to be useful.
What changed for users
Fewer stale-looking entries near lineup and lock windows.
Clearer expectations when a feed is late or incomplete.
More conservative behavior when the slate does not meet publication standards.
Release notes
Better messaging when a market feed returns no usable rows.
More consistent lock-window language across the daily product.
Additional pre-publication checks around data freshness.
P-26.05.006 · Almanac
Source-linked MLB news briefs
Posterior added a public news almanac that rewrites source facts into concise team, player, roster, injury, lineup, and league notes.
What changed for users
Users can read the context behind the slate without leaving the product.
Briefs keep the original source attached for verification.
Team desks now have a stronger daily editorial layer.
Release notes
New public /news surface.
Team-aware news navigation.
Source links and external video references where available.
P-26.05.005 · Trust
Public proof surfaces hardened
The public record, methodology, and accuracy pages were aligned so users can inspect the product by record and calibration instead of marketing claims.
What changed for users
More confidence that wins and losses are both represented.
Clearer path from a public claim to the supporting record.
A cleaner split between public proof and subscriber-only detail.
Release notes
Updated public accuracy and methodology language.
Cleaner public dataset references.
Improved machine-readable discovery for crawlers and AI agents.
P-26.05.004 · Developers
API desk prepared for early users
Posterior prepared the developer surface for users who want model probabilities, accuracy snapshots, and calibration data in their own workflow.
What changed for users
Power users can understand the API shape before requesting access.
API output is framed around stable data contracts instead of screenshots.
The developer surface points to the same proof systems as the web app.
Release notes
Public /developers page.
Endpoint descriptions for picks, accuracy, and calibration.
Clearer API positioning for early-access users.
P-26.05.003 · Market Context
Market reference coverage improved
Posterior improved how the product checks whether a daily entry has enough market context to be useful before it reaches the slate.
What changed for users
Daily entries are less likely to be shown without a useful market reference.
The product is more cautious when market context is thin.
Users get a better read on price versus fair value.
Release notes
More conservative treatment of entries with incomplete market context.
Clearer price-versus-probability framing.
Improved daily slate quality controls.
P-26.05.002 · Signals
Signal coverage made auditable
Posterior formalized the public signal map so users can understand the kinds of baseball, market, and operational context that influence the product.
What changed for users
Users can see the breadth of context without needing implementation details.
Signal availability and actual probability movement can be checked separately.
The product is clearer about why some slates stay quiet.
Release notes
Public signal categories organized by batter, pitcher, team context, market, and operations.
Internal coverage checks for evidence and probability movement.
More honest handling of missing or neutral context.
P-26.05.001 · Foundation
Posterior MLB almanac foundation
Posterior launched the core MLB almanac direction: daily probabilities, team desks, public proof, and a subscriber product built around calibrated baseball context.
What changed for users
A single place for daily MLB probability context.
Public proof surfaces alongside subscriber-only workflow tools.
A product identity centered on calibration, uncertainty, and accountability.
Release notes
Daily MLB slate experience.
Team desks and public almanac pages.
Subscriber product routes for picks, markets, accuracy, recap, and bet logging.
03 / Versioning
Posterior release IDs.
Each public update gets a receipt in the form P-YY.MM.NNN. The prefix identifies Posterior, the middle identifies the release month, and the final number is the public release count for that month.