Free to play · no money · graded by the box score
Think you know baseball? Prove it.
Make tonight's calls, and real MLB outcomes grade them — no money, no sportsbook, just the box score. Build a Baseball IQ, represent your club, and keep the receipts. Posterior grades its own model the same way, in public, losses included.
216–119 settled on the favorites board since Sep 2, 2026 · delayed ledger, CC BY 4.0
How the model worksOne engineer. One model. One sport.
01 / MLB right now
What is happening now.
⌘ K
Enter at least two characters to search.
Pre-Game · 2:20 PM
Pittsburgh Piratesat
Chicago CubsOpen game →Scheduled · 6:40 PM
Colorado Rockiesat
Detroit TigersOpen game →Scheduled · 6:45 PM
Los Angeles Angelsat
Washington NationalsOpen game →Scheduled · 7:05 PM
New York Metsat
New York YankeesOpen game →Scheduled · 7:07 PM
Baltimore Oriolesat
Toronto Blue JaysOpen game →
Full scoreboard →Pittsburgh PiratesatChicago CubsOpen game →Scheduled · 6:40 PMColorado RockiesatDetroit TigersOpen game →Scheduled · 6:45 PMLos Angeles AngelsatWashington NationalsOpen game →Scheduled · 7:05 PMNew York MetsatNew York YankeesOpen game →Scheduled · 7:07 PMBaltimore OriolesatToronto Blue JaysOpen game →02 / Your club
Understand your club. Build what comes next.
Loading your club desk…
03 / Player discovery
Start with the players shaping the day.
Posterior Play · free
Make your calls. Beat the machine.
A free daily card of real baseball calls — no cash, no odds. Posterior takes its own side of every one, and your record against it is kept call by call.
Play today's card →04 / Posterior Decisions
We do not predict games. We price them.
Chicago Cubs · 1+ hits Over 0.5
Nico Hoerner
- Posterior Price
- -181
- Action Window
- -172 or better
- Receipt
- Pending · grades after the final
Access
A baseball account first. Decision intelligence when you want it.
Public proof
Every official conclusion leaves a receipt.
335official Decisions
64.5%hit rate
216–119W–L
Favorites board since Sep 2, 2026. Previous board (edge policy) Jun 7 – Sep 1, 2026: 215–341. Audited replay through Jun 6, 2026: 1,405–751 · offline replay, not the live board.
Open calibration and record →§ On the name
pos·te·ri·or
/pɒˈstɪərɪə/ · adjective & noun
- 1Statistics. the distribution of a belief once the evidence is in — what Bayes' theorem turns a prior into. — this is the one we mean.
- 2Anatomy, informal. the hindquarters; the seat; the rump. — yes. we are aware.
“We named it for the math. The second reading is a happy accident we've chosen to wear with dignity — cheek included.”
Free to play · no money · graded by the box score
Think you know baseball? Prove it.
Make tonight's calls, and real MLB outcomes grade them — no money, no sportsbook, just the box score. Build a Baseball IQ, represent your club, and keep the receipts. Posterior grades its own model the same way, in public, losses included.
216–119 settled on the favorites board since Sep 2, 2026 · delayed ledger, CC BY 4.0
How the model worksOne engineer. One model. One sport.
01 / MLB right now
Games and source-linked context
What is happening now—without synthetic activity.
Game states come from the official schedule. Wire items retain their source. Empty upstream windows stay empty.
GamesFull scoreboard →
⌘ K
Enter at least two characters to search.
Pre-Game
Pittsburgh PiratesatChicago Cubs
Scheduled
Colorado RockiesatDetroit Tigers
Scheduled
Los Angeles AngelsatWashington Nationals
Scheduled
New York MetsatNew York Yankees
Scheduled
Baltimore OriolesatToronto Blue Jays
Scheduled
Kansas City Royalsat
Boston Red Sox
Posterior WireOpen the Wire →
Current source-linked briefs are unavailable. Posterior is not filling the gap with synthetic activity.
Explore the baseball day
CHC
03 / Your club
Roster reality, not a simulator
Understand your club. Build what comes next.
Posterior separates sourced roster facts from its outlook and from the assumptions you choose in Roster Lab.
Loading your club desk…
04 / Player discovery
One focused rail
Start with the players shaping the day.
This descriptive form comparison is supporting evidence, not a Posterior Decision. Hot form never overrides price or publication policy.
Player form movementLast 14 days vs last 30 days
Swipe, scroll or tab through current player dossiers.
ActiveTEX · 2B
Nicky Lopez
66.7% recent average+34.5 pts versus last 30 days
Scheduled · 9:40 PM EDT
Injured 10-DayLAA · 2B
Adam Frazier
7.7% recent average-25.6 pts versus last 30 days
Scheduled · 6:45 PM EDT
ActiveKC · CF
Lane Thomas
0.0% recent average-18.8 pts versus last 30 days
Scheduled · 7:10 PM EDT
ActiveMIA · 2B
Xavier Edwards
10.0% recent average-17.0 pts versus last 30 days
Scheduled · 7:10 PM EDT
Injured 10-DaySD · C
Freddy Fermin
0.0% recent average-16.7 pts versus last 30 days
Scheduled · 10:15 PM EDT
Suspended # daysBOS · 1B
Willson Contreras
7.1% recent average-16.6 pts versus last 30 days
Scheduled · 7:10 PM EDT
ActiveCIN · SS
Elly De La Cruz
47.7% recent average+15.0 pts versus last 30 days
Scheduled · 7:45 PM EDT
Injured 60-DayNYM · CF
Luis Robert Jr.
10.0% recent average-14.1 pts versus last 30 days
Scheduled · 7:05 PM EDT
05 / Posterior Play
Free · no cash, no odds
Make your calls. Beat the machine.
A free daily card of real baseball calls. Posterior takes its own side of every one — your record against it, kept honestly, call by call.
Five printed calls a day. Pick your sides, watch them settle from the box score, and keep a career record against Posterior's own number.
Play today's cardPosterior
06 / Posterior Decisions
Price → Action Window → Receipt
We do not predict games. We price them.
A Posterior Decision preserves the filed model view, exact captured quote, price limit and eventual result. Later market movement never rewrites the original receipt.
Current public Decision exampleOFFICIAL · FILED
Current public recChicago Cubs · Pittsburgh Pirates at Chicago Cubs
Nico Hoerner
1+ hits Over 0.5 · 0.501 · Posterior Price-18164.5% independent filed probability
→02 · Action Window-172 or better2.0% minimum EV policy
→03 · Permanent ReceiptPending · grades after the finalSep 11, 2026
- Captured quote
- -225 · prophetx2 min at lock
- Market probability
- 68.3%-3.8 pts model gap
- Quote captured
- Sep 11, 12:15 PM EDTnot a decorative live timestamp
- Publication
- Sep 11, 12:17 PM EDTproduction-lock:bayesian · sharp-data-v2
07 / Access
Explore, decide, build
A baseball account first. Decision intelligence when you want it.
A free Posterior account lets fans personalize their club context and participate where the product supports it. Pro completes the independent Decision workflow. Builder exposes Posterior’s supported machine contract.
Play, and keep the receiptsalways
Posterior Account
$0
Personalize your Primary Club, join eligible Clubhouse calls, follow players, explore team context and inspect public MLB evidence with a free account.
- Posterior Play — tonight's card, graded from the box score
- Baseball IQ and a public baseball resume with your settled record
- Clubhouse calls with the evidence frozen at publish
- Explicit paused, unpublished, no-opportunity, and unavailable states
- Team desks, Front Office roster outlooks and the Roster Lab
Live decision intelligenceper month
Pro
$29/mo
Know what Posterior thinks the outcome is worth, the exact price that still qualifies, where the best eligible quote exists now, and what changed afterward.
- Posterior Price: independent probability and fair value
- Action Window: the worst price that still clears policy
- Current quote: exact eligible sportsbook, price, and freshness
- Price-only WAIT triggers kept separate from pending inputs and policy rejections
- Decision timeline and alerts when state or price materially changes
Machine accessAPI add-on
Builder API
$99 add-on
Structured access to Posterior’s supported probabilities, immutable decisions, market states, public evidence and player context.
Requires Pro · $128/mo combined before applicable tax
- Public OpenAPI schema and delayed resolved CSV
- Bearer-protected supported production endpoints
- Active Posterior Pro plus Builder add-on required
- 100 requests per minute per active key by default
08 / Apple ecosystem
Posterior for iPhone and Apple Watch · private beta
The MLB desk, wherever the game finds you.
Open the complete intelligence desk on iPhone, follow current game context through Live Activities and Dynamic Island, and carry the same trusted state onto widgets and Apple Watch.
iPhone deskToday, Live, Markets, Wire and the full MLB Almanac.
Live at a glanceNative Live Activities and Dynamic Island game context.
Home + Lock ScreenPosterior widgets built for quick, honest state checks.
Apple WatchA companion desk with Decisions, games, standings and Wire.
Included in the current private betaPrivate beta available to invited TestFlight testers · Not yet available on the App Store
09 / Public proof
Auditable restraint
Every official conclusion leaves a receipt.
Posterior preserves the filed probability and available price, then records what happened. Current market state never rewrites the original filing.
Permanent public recordOpen calibration and record →
What Posterior knew. When it knew it. What happened next.
Losing Decisions remain visible. A provider failure stays unavailable. A WAIT is not repackaged as an unofficial recommendation. That restraint is the trust system.
335official Decisions resolved
216–119W–L through Sep 11, 2026
64.5%within this policy scope
0.224Brier score · lower is sharper
Diagnostic price-reference evidence · ROI -3.2% · 335 priced picks · flat 1u at captured prices
Evidence throughSep 11, 2026
Aggregate computedSep 11, 1:22 PM EDT
Latest settlementSep 10, 10:15 PM EDT
10 / Posterior system
One connected MLB desk
Know. Participate. Explore. Decide.
Posterior connects the baseball day without collapsing distinct evidence types into one score or opinion.
Know
Live games, sourced Wire context and current league state form the shared MLB desk.
→Participate
Clubhouse questions let fans make evidence-attached calls without manufactured consensus.
→Explore
Team, player and Front Office surfaces connect roster facts, Posterior assessments and explicit assumptions.
→Decide
Posterior Decisions add independent probability, price discipline and permanent receipts for users who want them.
§ On the name
pos·te·ri·or
/pɒˈstɪərɪə/ · adjective & noun
- 1Statistics. the distribution of a belief once the evidence is in — what Bayes' theorem turns a prior into. — this is the one we mean.
- 2Anatomy, informal. the hindquarters; the seat; the rump. — yes. we are aware.
“We named it for the math. The second reading is a happy accident we've chosen to wear with dignity — cheek included.”
