Add NCAA Football CFP simulator (12-team bracket) (#278)

Fixes #124

* Add NCAA Football CFP simulator (12-team bracket)

Implements a Monte Carlo simulator for the College Football Playoff using
the 2024-present 12-team format. Elo/FPI ratings are entered manually via
the existing admin Elo Ratings page; championship futures odds can
optionally be blended in (60% Elo / 40% odds).

- Add CFP_12 bracket template (First Round not scoring, QFs onward score)
- Add generateCFP12Bracket() with correct seeding: 5v12, 6v11, 7v10, 8v9
  in First Round; seeds 1–4 receive QF byes
- Add NCAAFootballSimulator: 50k Monte Carlo sims, seeds teams by blended
  Elo+odds strength, tracks champion/finalist/SF/QF placement tiers
- Register ncaa_football_bracket simulator type in registry and schema enum
- Add migration 0071: ALTER TYPE simulator_type ADD VALUE 'ncaa_football_bracket'
- Add tests: 30 tests covering bracket template structure and simulator
  probability distributions, seeding, edge cases, futures blending

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Fix lint errors in NCAA Football CFP simulator

Replace non-null assertions with optional chaining, change let to const,
use toSorted() instead of sort(), and add a bump() helper to avoid
repeated map lookups with non-null assertions in simulateBracket.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Fix TS2345 in NCAA football simulator test

Add ?? 0 fallback so optional-chained probFirst is number, not number | undefined.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
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@ -633,6 +633,46 @@ export const FIFA_48: BracketTemplate = {
],
};
/**
* College Football Playoff (12 teams, 2024present format)
* First Round: 5v12, 6v11, 7v10, 8v9 (campus sites, no fantasy points)
* Quarterfinals: Seeds 14 (bye) vs first-round winners (scoring starts here)
* Semifinals: 4 2
* National Championship: 1 game
*/
export const CFP_12: BracketTemplate = {
id: "cfp_12",
name: "College Football Playoff (12 teams)",
totalTeams: 12,
scoringStartsAtRound: "Quarterfinals",
rounds: [
{
name: "First Round",
matchCount: 4,
feedsInto: "Quarterfinals",
isScoring: false, // 8 seeds play, top 4 have byes
},
{
name: "Quarterfinals",
matchCount: 4,
feedsInto: "Semifinals",
isScoring: true, // Losers share 5th8th
},
{
name: "Semifinals",
matchCount: 2,
feedsInto: "National Championship",
isScoring: true, // Losers share 3rd4th
},
{
name: "National Championship",
matchCount: 1,
feedsInto: null,
isScoring: true, // Winner 1st, loser 2nd
},
],
};
/**
* All available bracket templates
*/
@ -646,6 +686,7 @@ export const BRACKET_TEMPLATES: Record<string, BracketTemplate> = {
afl_10: AFL_10,
fifa_48: FIFA_48,
darts_128: DARTS_128,
cfp_12: CFP_12,
};
/**

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@ -0,0 +1,93 @@
import { describe, it, expect } from "vitest";
import { CFP_12, BRACKET_TEMPLATES, getScoringRoundType } from "~/lib/bracket-templates";
describe("CFP_12 Bracket Template", () => {
describe("Template structure", () => {
it("has correct total teams", () => {
expect(CFP_12.totalTeams).toBe(12);
});
it("has 4 rounds", () => {
expect(CFP_12.rounds).toHaveLength(4);
});
it("has correct round names", () => {
expect(CFP_12.rounds[0].name).toBe("First Round");
expect(CFP_12.rounds[1].name).toBe("Quarterfinals");
expect(CFP_12.rounds[2].name).toBe("Semifinals");
expect(CFP_12.rounds[3].name).toBe("National Championship");
});
it("has correct match counts per round", () => {
expect(CFP_12.rounds[0].matchCount).toBe(4); // 8 seeds play, 4 byes
expect(CFP_12.rounds[1].matchCount).toBe(4); // 8 → 4
expect(CFP_12.rounds[2].matchCount).toBe(2); // 4 → 2
expect(CFP_12.rounds[3].matchCount).toBe(1); // 2 → 1
});
it("has correct round advancement chain", () => {
expect(CFP_12.rounds[0].feedsInto).toBe("Quarterfinals");
expect(CFP_12.rounds[1].feedsInto).toBe("Semifinals");
expect(CFP_12.rounds[2].feedsInto).toBe("National Championship");
expect(CFP_12.rounds[3].feedsInto).toBeNull();
});
});
describe("Scoring configuration", () => {
it("scoring starts at Quarterfinals", () => {
expect(CFP_12.scoringStartsAtRound).toBe("Quarterfinals");
});
it("First Round is not scoring", () => {
expect(CFP_12.rounds[0].isScoring).toBe(false);
});
it("Quarterfinals is scoring", () => {
expect(CFP_12.rounds[1].isScoring).toBe(true);
});
it("Semifinals is scoring", () => {
expect(CFP_12.rounds[2].isScoring).toBe(true);
});
it("National Championship is scoring", () => {
expect(CFP_12.rounds[3].isScoring).toBe(true);
});
});
describe("Template ID and registry", () => {
it("has id cfp_12", () => {
expect(CFP_12.id).toBe("cfp_12");
});
it("is registered in BRACKET_TEMPLATES", () => {
expect(BRACKET_TEMPLATES["cfp_12"]).toBeDefined();
expect(BRACKET_TEMPLATES["cfp_12"]).toBe(CFP_12);
});
});
describe("getScoringRoundType", () => {
it("classifies Quarterfinals as quarterfinals (losers share 5th8th)", () => {
expect(getScoringRoundType("Quarterfinals", CFP_12)).toBe("quarterfinals");
});
it("classifies Semifinals as semifinals (losers share 3rd4th)", () => {
expect(getScoringRoundType("Semifinals", CFP_12)).toBe("semifinals");
});
it("classifies National Championship as finals", () => {
expect(getScoringRoundType("National Championship", CFP_12)).toBe("finals");
});
it("returns null for First Round (non-scoring)", () => {
expect(getScoringRoundType("First Round", CFP_12)).toBeNull();
});
});
describe("Total matches", () => {
it("has 11 total matches across all rounds", () => {
const total = CFP_12.rounds.reduce((sum, r) => sum + r.matchCount, 0);
expect(total).toBe(11); // 4 + 4 + 2 + 1
});
});
});

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@ -355,6 +355,11 @@ export async function generateBracketFromTemplate(
return await generateAFL10Bracket(eventId, template, participantIds);
}
// CFP 12 requires special handling for bye weeks (seeds 14 skip First Round)
if (templateId === "cfp_12") {
return await generateCFP12Bracket(eventId, template, participantIds);
}
const matches: NewPlayoffMatch[] = [];
// Generate matches for each round in the template
@ -1069,3 +1074,97 @@ export async function assignParticipantsToKnockout(
});
}
}
/**
* Generate College Football Playoff 12-team bracket.
*
* First Round (seeds 512, 4 games, not scoring):
* Match 1: 5 vs 12
* Match 2: 6 vs 11
* Match 3: 7 vs 10
* Match 4: 8 vs 9
*
* Quarterfinals (4 games, scoring starts):
* Match 1: 1 vs First Round match 4 winner (8/9)
* Match 2: 4 vs First Round match 1 winner (5/12)
* Match 3: 3 vs First Round match 2 winner (6/11)
* Match 4: 2 vs First Round match 3 winner (7/10)
*
* Semifinals and National Championship: TBD vs TBD
*/
async function generateCFP12Bracket(
eventId: string,
template: BracketTemplate,
participantIds?: string[]
): Promise<PlayoffMatch[]> {
const matches: NewPlayoffMatch[] = [];
// First Round: seeds 512 (indices 411), top 4 (indices 03) have byes
const firstRoundSeeding: [number, number][] = [
[4, 11], // 5 vs 12
[5, 10], // 6 vs 11
[6, 9], // 7 vs 10
[7, 8], // 8 vs 9
];
const firstRound = template.rounds[0]; // "First Round"
for (let i = 0; i < firstRoundSeeding.length; i++) {
const [s1, s2] = firstRoundSeeding[i];
matches.push({
scoringEventId: eventId,
round: firstRound.name,
matchNumber: i + 1,
participant1Id: participantIds ? participantIds[s1] : null,
participant2Id: participantIds ? participantIds[s2] : null,
isComplete: false,
isScoring: false,
templateRound: firstRound.name,
seedInfo: `${s1 + 1} vs ${s2 + 1}`,
});
}
// Quarterfinals: seeds 14 (indices 03) receive byes, face First Round winners
// Matchup order mirrors CFP bracket: 1 vs 8/9 winner, 4 vs 5/12 winner, etc.
const quarterfinalsSeeding: [number, string][] = [
[0, "1 vs TBD"], // 1 seed vs First Round match 4 winner (8v9)
[3, "4 vs TBD"], // 4 seed vs First Round match 1 winner (5v12)
[2, "3 vs TBD"], // 3 seed vs First Round match 2 winner (6v11)
[1, "2 vs TBD"], // 2 seed vs First Round match 3 winner (7v10)
];
const quarterfinalsRound = template.rounds[1]; // "Quarterfinals"
for (let i = 0; i < quarterfinalsSeeding.length; i++) {
const [byeSeedIndex, seedInfo] = quarterfinalsSeeding[i];
matches.push({
scoringEventId: eventId,
round: quarterfinalsRound.name,
matchNumber: i + 1,
participant1Id: participantIds ? participantIds[byeSeedIndex] : null,
participant2Id: null, // Filled when First Round winner is known
isComplete: false,
isScoring: true,
templateRound: quarterfinalsRound.name,
seedInfo,
});
}
// Semifinals and National Championship: all TBD
for (let roundIndex = 2; roundIndex < template.rounds.length; roundIndex++) {
const round = template.rounds[roundIndex];
for (let i = 0; i < round.matchCount; i++) {
matches.push({
scoringEventId: eventId,
round: round.name,
matchNumber: i + 1,
participant1Id: null,
participant2Id: null,
isComplete: false,
isScoring: round.isScoring,
templateRound: round.name,
seedInfo: null,
});
}
}
return await createManyPlayoffMatches(matches);
}

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@ -0,0 +1,227 @@
import { describe, it, expect, vi, beforeEach, type MockInstance } from "vitest";
import { NCAAFootballSimulator } from "../ncaa-football-simulator";
vi.mock("~/database/context", () => ({
database: vi.fn(),
}));
// Use real implementations of pure math functions to avoid mock call accumulation
// across 50k-iteration simulations. Only mock convertFuturesToElo (complex behavior).
vi.mock("~/services/probability-engine", async (importOriginal) => {
const actual = await importOriginal() as Record<string, unknown>;
return {
...actual,
convertFuturesToElo: vi.fn((oddsInput: { participantId: string; odds: number }[]) => {
return new Map(oddsInput.map((o, i) => [o.participantId, 1600 - i * 50]));
}),
};
});
// ─── Helpers ──────────────────────────────────────────────────────────────────
const TEAM_IDS = Array.from({ length: 12 }, (_, i) => `team-${i + 1}`);
/** Build EV rows with sourceElo ratings (descending — team-1 is best). */
function makeEvRows(
ids: string[],
opts: { includeOdds?: boolean } = {}
) {
return ids.map((participantId, i) => ({
participantId,
sourceElo: 1700 - i * 50, // 1700, 1650, 1600, …
sourceOdds: opts.includeOdds ? (i === 0 ? -200 : 300 + i * 50) : null,
}));
}
function makeParticipants(ids: string[]) {
return ids.map((id) => ({ id }));
}
// ─── Tests ────────────────────────────────────────────────────────────────────
describe("NCAAFootballSimulator", () => {
let mockDb: { select: MockInstance };
let selectCallCount: number;
beforeEach(async () => {
selectCallCount = 0;
const { database } = await import("~/database/context");
mockDb = { select: vi.fn() };
(database as unknown as MockInstance).mockReturnValue(mockDb);
});
function setupMockDb(participantIds: string[], opts: { includeOdds?: boolean } = {}) {
const participants = makeParticipants(participantIds);
const evRows = makeEvRows(participantIds, opts);
mockDb.select.mockImplementation(() => {
const callIndex = selectCallCount++;
const data = callIndex === 0 ? participants : evRows;
return { from: vi.fn().mockReturnValue({ where: vi.fn().mockResolvedValue(data) }) };
});
}
// ── Post-bracket mode (exactly 12 teams) ─────────────────────────────────
describe("post-bracket mode (exactly 12 teams)", () => {
it("returns one result per participant", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
expect(results).toHaveLength(12);
});
it("all probabilities are between 0 and 1", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
for (const r of results) {
const p = r.probabilities;
expect(p.probFirst).toBeGreaterThanOrEqual(0);
expect(p.probFirst).toBeLessThanOrEqual(1);
expect(p.probSecond).toBeGreaterThanOrEqual(0);
expect(p.probSecond).toBeLessThanOrEqual(1);
}
});
it("top-rated team has highest champion probability", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
const byId = new Map(results.map((r) => [r.participantId, r]));
expect(byId.get("team-1")?.probabilities.probFirst).toBeGreaterThan(
byId.get("team-12")?.probabilities.probFirst ?? 0
);
});
it("probFirst sums to approximately 1.0", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
const total = results.reduce((sum, r) => sum + r.probabilities.probFirst, 0);
expect(total).toBeCloseTo(1.0, 1);
});
it("probSecond sums to approximately 1.0", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
const total = results.reduce((sum, r) => sum + r.probabilities.probSecond, 0);
expect(total).toBeCloseTo(1.0, 1);
});
it("probThird equals probFourth for every team (tied SF placement)", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
for (const r of results) {
expect(r.probabilities.probThird).toBeCloseTo(r.probabilities.probFourth, 10);
}
});
it("probFifth through probEighth are equal for every team (tied QF placement)", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
for (const r of results) {
const p = r.probabilities;
expect(p.probFifth).toBeCloseTo(p.probSixth, 10);
expect(p.probSixth).toBeCloseTo(p.probSeventh, 10);
expect(p.probSeventh).toBeCloseTo(p.probEighth, 10);
}
});
it("weakest team has very low champion probability", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
const byId = new Map(results.map((r) => [r.participantId, r]));
// team-12 (Elo 1150) vs team-1 (Elo 1700): 550-point gap → should rarely win
expect(byId.get("team-12")?.probabilities.probFirst).toBeLessThan(0.02);
});
it("source is cfp_monte_carlo", async () => {
setupMockDb(TEAM_IDS);
const results = await new NCAAFootballSimulator().simulate("season-1");
for (const r of results) {
expect(r.source).toBe("cfp_monte_carlo");
}
});
it("uses futures odds when sourceOdds present", async () => {
setupMockDb(TEAM_IDS, { includeOdds: true });
const results = await new NCAAFootballSimulator().simulate("season-1");
expect(results).toHaveLength(12);
const total = results.reduce((s, r) => s + r.probabilities.probFirst, 0);
expect(total).toBeCloseTo(1.0, 1);
});
});
// ── Pre-bracket mode (>12 teams — probabilistic selection) ───────────────
describe("pre-bracket mode (>12 teams)", () => {
it("returns one result per participant when pool is larger than 12", async () => {
const twentyTeams = Array.from({ length: 20 }, (_, i) => `team-${i + 1}`);
setupMockDb(twentyTeams);
const results = await new NCAAFootballSimulator().simulate("season-1");
expect(results).toHaveLength(20);
});
it("probFirst still sums to ~1.0 across all teams (one champion per sim)", async () => {
const twentyTeams = Array.from({ length: 20 }, (_, i) => `team-${i + 1}`);
setupMockDb(twentyTeams);
const results = await new NCAAFootballSimulator().simulate("season-1");
const total = results.reduce((sum, r) => sum + r.probabilities.probFirst, 0);
expect(total).toBeCloseTo(1.0, 1);
});
it("top team has much higher probFirst than bottom team in larger pool", async () => {
const twentyTeams = Array.from({ length: 20 }, (_, i) => `team-${i + 1}`);
setupMockDb(twentyTeams);
const results = await new NCAAFootballSimulator().simulate("season-1");
const byId = new Map(results.map((r) => [r.participantId, r]));
// team-1 (Elo 1700) should win far more often than team-20 (Elo 750)
expect(byId.get("team-1")?.probabilities.probFirst).toBeGreaterThan(
(byId.get("team-20")?.probabilities.probFirst ?? 0) * 10
);
});
it("bottom-pool teams (large Elo gap) rarely appear in champion slot", async () => {
const twentyTeams = Array.from({ length: 20 }, (_, i) => `team-${i + 1}`);
setupMockDb(twentyTeams);
const results = await new NCAAFootballSimulator().simulate("season-1");
const byId = new Map(results.map((r) => [r.participantId, r]));
// team-19 and team-20 have Elos of 800 and 750 — far below the top 12 (~1150+)
// With softmax T=100, their selection weight is negligible
expect(byId.get("team-19")?.probabilities.probFirst).toBeLessThan(0.01);
expect(byId.get("team-20")?.probabilities.probFirst).toBeLessThan(0.01);
});
it("uses futures odds as selection weights when provided", async () => {
const twentyTeams = Array.from({ length: 20 }, (_, i) => `team-${i + 1}`);
setupMockDb(twentyTeams, { includeOdds: true });
const results = await new NCAAFootballSimulator().simulate("season-1");
expect(results).toHaveLength(20);
const total = results.reduce((s, r) => s + r.probabilities.probFirst, 0);
expect(total).toBeCloseTo(1.0, 1);
});
});
// ── Error cases ───────────────────────────────────────────────────────────
describe("error cases", () => {
it("throws when fewer than 12 participants provided", async () => {
const elevenTeams = TEAM_IDS.slice(0, 11);
let call = 0;
mockDb.select.mockImplementation(() => {
const data = call++ === 0 ? makeParticipants(elevenTeams) : makeEvRows(elevenTeams);
return { from: vi.fn().mockReturnValue({ where: vi.fn().mockResolvedValue(data) }) };
});
await expect(new NCAAFootballSimulator().simulate("season-1")).rejects.toThrow(/at least 12/);
});
it("throws when participant list is empty", async () => {
let call = 0;
mockDb.select.mockImplementation(() => {
const data = call++ === 0 ? [] : [];
return { from: vi.fn().mockReturnValue({ where: vi.fn().mockResolvedValue(data) }) };
});
await expect(new NCAAFootballSimulator().simulate("season-1")).rejects.toThrow(/at least 12/);
});
});
});

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@ -0,0 +1,350 @@
/**
* NCAA Football CFP Simulator
*
* Monte Carlo simulation of the College Football Playoff (12-team format, 2024present).
*
* Algorithm:
* 1. Load all participants for the sports season from DB
* 2. Load Elo/FPI ratings from participantExpectedValues.sourceElo
* (entered via Admin Elo Ratings page; use FPI, S&P+, or any Elo-scale rating)
* 3. If sourceOdds (American format) are also stored, build a normalized selection
* weight from implied championship probability (used for field selection in step 4)
* and blend into per-game win probability (ELO_WEIGHT=0.6 / ODDS_WEIGHT=0.4).
* 4. Per simulation, select 12 teams for the CFP field:
* - If the pool has exactly 12 teams: use all of them (post-bracket mode).
* - If the pool has >12 teams: weighted sample without replacement using each
* team's selection weight odds-derived if available, Elo-based otherwise.
* Teams with stronger championship odds are sampled more often, naturally
* encoding both selection probability and bracket strength into one signal.
* 5. Seed the 12 selected teams by Elo (best Elo = seed 1).
* 6. Simulate the CFP bracket:
* First Round (not scoring): 5v12, 6v11, 7v10, 8v9
* Quarterfinals (scoring): 1 vs 8/9w, 4 vs 5/12w, 3 vs 6/11w, 2 vs 7/10w
* Semifinals (scoring): QF1w vs QF2w, QF3w vs QF4w
* National Championship: SF1w vs SF2w
* 7. Track placement counts per scoring tier across all simulations.
* 8. Convert counts to probability distributions.
*
* Pre-bracket vs post-bracket mode:
* Pre-bracket (>12 participants): probabilities reflect both selection uncertainty
* and bracket performance. A bubble team might appear in only 40% of simulated
* fields, so its champion probability accounts for that.
* Post-bracket (exactly 12 participants): deterministic field, bracket-only sim.
*
* Win probability (per game): eloWinProbability() from probability-engine (400-divisor).
* Blended win probability: ELO_WEIGHT * eloProb + ODDS_WEIGHT * oddsProb (when odds present).
*
* Selection weight (pre-bracket mode):
* With sourceOdds: normalized implied championship probability (vig removed, sums to 1).
* Without sourceOdds: softmax on Elo with temperature SELECTION_TEMP (sharply favors
* higher-rated teams a 200-point Elo gap yields ~7× selection weight difference).
*
* Placement tiers SimulationProbabilities mapping:
* probFirst = National Champion (1 per sim)
* probSecond = Championship game loser (1 per sim)
* probThird / probFourth = Semifinal losers (2 per sim split evenly)
* probFifthprobEighth = Quarterfinal losers (4 per sim split evenly)
* First Round losers all 0 (score 0 fantasy points)
* Teams not selected all 0 (not in field for that sim)
*
* Admin setup:
* 1. Create a Sport with simulatorType = "ncaa_football_bracket"
* 2. Create a Sports Season and add all contender participants (12 or more)
* 3. Enter FPI ratings via Admin Elo Ratings (stored as sourceElo)
* 4. Optionally enter championship futures odds via Admin Futures Odds (sourceOdds)
* strongly recommended for pre-bracket mode; drives both selection and bracket strength
* 5. Run simulation via Admin Simulate
*/
import { database } from "~/database/context";
import { eq } from "drizzle-orm";
import * as schema from "~/database/schema";
import {
convertAmericanOddsToProbability,
convertFuturesToElo,
eloWinProbability,
} from "~/services/probability-engine";
import type { Simulator, SimulationResult } from "./types";
// ─── Simulation parameters ────────────────────────────────────────────────────
const NUM_SIMULATIONS = 50_000;
const BRACKET_SIZE = 12;
/**
* Blend weights for per-game win probability when sourceOdds are present.
* Lower Elo weight than other sports (0.7) gives more influence to Vegas
* championship odds, which are highly informative in college football.
*/
const ELO_WEIGHT = 0.6;
const ODDS_WEIGHT = 1 - ELO_WEIGHT;
/**
* Softmax temperature for Elo-based selection weights (pre-bracket mode, no odds).
* At T=100, a 200-point Elo gap produces ~7× weight difference enough to strongly
* favour the top teams while still giving bubble teams meaningful selection probability.
*/
const SELECTION_TEMP = 100;
// ─── Types ────────────────────────────────────────────────────────────────────
interface Team {
participantId: string;
elo: number;
/** Normalized futures win probability (01). Used for blending per-game win prob. */
oddsProb: number;
/**
* Weight used for probabilistic CFP field selection (pre-bracket mode only).
* Derived from oddsProb when available; otherwise softmax on Elo.
*/
selectionWeight: number;
}
// ─── Helpers ─────────────────────────────────────────────────────────────────
/**
* Blended win probability for team1 vs team2.
* Falls back to pure Elo when no futures data is present.
*/
function blendedWinProb(team1: Team, team2: Team): number {
const eloProbValue = eloWinProbability(team1.elo, team2.elo);
if (team1.oddsProb === 0 && team2.oddsProb === 0) {
return eloProbValue;
}
const oddsSum = team1.oddsProb + team2.oddsProb;
const oddsProbValue = oddsSum > 0 ? team1.oddsProb / oddsSum : 0.5;
return ELO_WEIGHT * eloProbValue + ODDS_WEIGHT * oddsProbValue;
}
function simGame(team1: Team, team2: Team): { winner: Team; loser: Team } {
const p1Wins = Math.random() < blendedWinProb(team1, team2);
return p1Wins
? { winner: team1, loser: team2 }
: { winner: team2, loser: team1 };
}
/**
* Weighted sample without replacement selects `n` teams from `pool` where each
* team's probability of being drawn is proportional to its selectionWeight.
* Returns the selected teams sorted by Elo descending (seed 1 = best Elo).
*/
function sampleBracketField(pool: Team[], n: number): Team[] {
const remaining = [...pool];
const selected: Team[] = [];
for (let i = 0; i < n; i++) {
const totalWeight = remaining.reduce((sum, t) => sum + t.selectionWeight, 0);
let r = Math.random() * totalWeight;
let j = 0;
for (; j < remaining.length - 1; j++) {
r -= remaining[j].selectionWeight;
if (r <= 0) break;
}
selected.push(remaining[j]);
remaining.splice(j, 1);
}
// Seed by Elo so that the best team in the sampled field is always seed 1.
return selected.toSorted((a, b) => b.elo - a.elo);
}
// ─── Bracket simulation ───────────────────────────────────────────────────────
interface PlacementCounts {
champion: number;
finalist: number;
sfLoser: number;
qfLoser: number;
}
/**
* Simulate one full 12-team CFP bracket.
*
* Seeding (teams sorted bestworst Elo, index 0 = seed 1):
* First Round: [4]v[11], [5]v[10], [6]v[9], [7]v[8]
* Quarterfinals: [0] vs fr4w, [3] vs fr1w, [2] vs fr2w, [1] vs fr3w
* Semifinals: qf1w vs qf2w, qf3w vs qf4w
* Championship: sf1w vs sf2w
*/
function simulateBracket(teams: Team[], counts: Map<string, PlacementCounts>): void {
// ── First Round (seeds 512) ───────────────────────────────────────────────
const fr1 = simGame(teams[4], teams[11]); // 5 vs 12
const fr2 = simGame(teams[5], teams[10]); // 6 vs 11
const fr3 = simGame(teams[6], teams[9]); // 7 vs 10
const fr4 = simGame(teams[7], teams[8]); // 8 vs 9
// ── Quarterfinals (seeds 14 get byes) ────────────────────────────────────
const qf1 = simGame(teams[0], fr4.winner); // 1 vs 8/9 winner
const qf2 = simGame(teams[3], fr1.winner); // 4 vs 5/12 winner
const qf3 = simGame(teams[2], fr2.winner); // 3 vs 6/11 winner
const qf4 = simGame(teams[1], fr3.winner); // 2 vs 7/10 winner
const bump = (id: string, key: keyof PlacementCounts) => {
const entry = counts.get(id);
if (entry) entry[key]++;
};
bump(qf1.loser.participantId, "qfLoser");
bump(qf2.loser.participantId, "qfLoser");
bump(qf3.loser.participantId, "qfLoser");
bump(qf4.loser.participantId, "qfLoser");
// ── Semifinals ────────────────────────────────────────────────────────────
const sf1 = simGame(qf1.winner, qf2.winner);
const sf2 = simGame(qf3.winner, qf4.winner);
bump(sf1.loser.participantId, "sfLoser");
bump(sf2.loser.participantId, "sfLoser");
// ── National Championship ─────────────────────────────────────────────────
const final = simGame(sf1.winner, sf2.winner);
bump(final.winner.participantId, "champion");
bump(final.loser.participantId, "finalist");
}
// ─── Simulator ────────────────────────────────────────────────────────────────
export class NCAAFootballSimulator implements Simulator {
async simulate(sportsSeasonId: string): Promise<SimulationResult[]> {
const db = database();
// 1. Load all participants for this sports season.
const participants = await db
.select({ id: schema.participants.id })
.from(schema.participants)
.where(eq(schema.participants.sportsSeasonId, sportsSeasonId));
if (participants.length < BRACKET_SIZE) {
throw new Error(
`CFP simulator requires at least ${BRACKET_SIZE} participants, ` +
`found ${participants.length}. Add all contender teams to the sports season.`
);
}
// 2. Load Elo/FPI ratings and optional futures odds in a single query.
const evRows = await db
.select({
participantId: schema.participantExpectedValues.participantId,
sourceElo: schema.participantExpectedValues.sourceElo,
sourceOdds: schema.participantExpectedValues.sourceOdds,
})
.from(schema.participantExpectedValues)
.where(eq(schema.participantExpectedValues.sportsSeasonId, sportsSeasonId));
// Build Elo and raw odds maps in a single pass.
const eloFromDb = new Map<string, number>();
const rawOddsProbs = new Map<string, number>();
for (const row of evRows) {
if (row.sourceElo !== null) {
eloFromDb.set(row.participantId, row.sourceElo);
}
if (row.sourceOdds !== null) {
rawOddsProbs.set(row.participantId, convertAmericanOddsToProbability(row.sourceOdds));
}
}
// 3. Build normalized odds probability map (vig removed).
const normalizedOddsMap = new Map<string, number>();
if (rawOddsProbs.size > 0) {
const rawSum = [...rawOddsProbs.values()].reduce((a, b) => a + b, 0);
for (const [id, prob] of rawOddsProbs) {
normalizedOddsMap.set(id, rawSum > 0 ? prob / rawSum : 0);
}
// Backfill Elo from futures for any team missing sourceElo.
if (eloFromDb.size < participants.length) {
const oddsInput = evRows
.filter((r) => r.sourceOdds !== null && !eloFromDb.has(r.participantId))
.map((r) => ({ participantId: r.participantId, odds: r.sourceOdds ?? 0 }));
if (oddsInput.length > 0) {
const oddsEloMap = convertFuturesToElo(oddsInput, "american");
for (const [id, elo] of oddsEloMap) {
eloFromDb.set(id, elo);
}
}
}
}
// 4. Build team list with Elo, oddsProb, and selectionWeight.
const hasOdds = normalizedOddsMap.size > 0;
const allTeams: Team[] = participants.map((p) => ({
participantId: p.id,
elo: eloFromDb.get(p.id) ?? 1500,
oddsProb: normalizedOddsMap.get(p.id) ?? 0,
selectionWeight: 0, // computed below
}));
if (hasOdds) {
// Selection weight = normalized championship implied probability.
// This encodes both "probability of making the field" and "strength once there."
for (const team of allTeams) {
team.selectionWeight = normalizedOddsMap.get(team.participantId) ?? 0;
}
} else {
// No odds: softmax on Elo so top-rated teams are strongly favoured.
const eloValues = allTeams.map((t) => t.elo);
const maxElo = Math.max(...eloValues);
// Subtract max for numerical stability before exp().
const expWeights = allTeams.map((t) => Math.exp((t.elo - maxElo) / SELECTION_TEMP));
const expSum = expWeights.reduce((a, b) => a + b, 0);
for (let i = 0; i < allTeams.length; i++) {
allTeams[i].selectionWeight = expWeights[i] / expSum;
}
}
const preBracketMode = participants.length > BRACKET_SIZE;
// In post-bracket mode (exactly 12), sort once and reuse the same field every sim.
const deterministicField = preBracketMode
? null
: [...allTeams].toSorted((a, b) => b.elo - a.elo);
// 5. Initialise placement count accumulators for all participants.
const allParticipantIds = participants.map((p) => p.id);
const counts = new Map<string, PlacementCounts>(
allParticipantIds.map((id) => [id, { champion: 0, finalist: 0, sfLoser: 0, qfLoser: 0 }])
);
// 6. Run Monte Carlo simulations.
for (let s = 0; s < NUM_SIMULATIONS; s++) {
const field = preBracketMode
? sampleBracketField(allTeams, BRACKET_SIZE)
: (deterministicField ?? []);
simulateBracket(field, counts);
}
// 7. Convert counts to probability distributions.
// SF losers: 2 per sim → each team's share = sfLoser / (2 * N).
// QF losers: 4 per sim → each team's share = qfLoser / (4 * N).
const sfDivisor = 2 * NUM_SIMULATIONS;
const qfDivisor = 4 * NUM_SIMULATIONS;
return allParticipantIds.map((id) => {
const c = counts.get(id) ?? { champion: 0, finalist: 0, sfLoser: 0, qfLoser: 0 };
const sfProb = c.sfLoser / sfDivisor;
const qfProb = c.qfLoser / qfDivisor;
return {
participantId: id,
probabilities: {
probFirst: c.champion / NUM_SIMULATIONS,
probSecond: c.finalist / NUM_SIMULATIONS,
probThird: sfProb,
probFourth: sfProb,
probFifth: qfProb,
probSixth: qfProb,
probSeventh: qfProb,
probEighth: qfProb,
},
source: "cfp_monte_carlo",
};
});
}
}

View file

@ -24,6 +24,7 @@ import { MLBSimulator } from "./mlb-simulator";
import { NFLSimulator } from "./nfl-simulator";
import { WNBASimulator } from "./wnba-simulator";
import { WorldCupSimulator } from "./world-cup-simulator";
import { NCAAFootballSimulator } from "./ncaa-football-simulator";
export const SIMULATOR_TYPES = [
"f1_standings",
@ -44,6 +45,7 @@ export const SIMULATOR_TYPES = [
"world_cup",
"darts_bracket",
"cs2_major_qualifying_points",
"ncaa_football_bracket",
] as const;
export type SimulatorType = typeof SIMULATOR_TYPES[number];
@ -143,6 +145,10 @@ const REGISTRY: Record<SimulatorType, { info: SimulatorInfo; create: () => Simul
info: { name: "CS2 Major Qualifying Points Monte Carlo", description: "Simulates 2 CS2 Majors per season (3 Swiss stages: Opening Bo1, Elimination Bo1, Decider Bo3, then Champions Stage single-elimination). Awards QP by final placement; ranks teams by total QP across both majors. Stage 3 exits (placements 916) are sub-ranked by W-L record." },
create: () => new CSMajorSimulator(),
},
ncaa_football_bracket: {
info: { name: "NCAA Football CFP Monte Carlo", description: "Simulates the 12-team College Football Playoff bracket using Elo/FPI ratings entered via Admin → Elo Ratings. Optionally blends with championship futures odds (60% Elo / 40% odds). Seeds 14 receive first-round byes; First Round losers score 0 points." },
create: () => new NCAAFootballSimulator(),
},
};
export function getSimulator(simulatorType: SimulatorType): Simulator {

View file

@ -101,6 +101,7 @@ export const simulatorTypeEnum = pgEnum("simulator_type", [
"world_cup",
"darts_bracket",
"cs2_major_qualifying_points",
"ncaa_football_bracket",
]);
export const playoffMatchGameStatusEnum = pgEnum("playoff_match_game_status", [

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@ -0,0 +1 @@
ALTER TYPE "public"."simulator_type" ADD VALUE 'ncaa_football_bracket';

File diff suppressed because it is too large Load diff

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@ -505,6 +505,13 @@
"when": 1775528386356,
"tag": "0071_many_nico_minoru",
"breakpoints": true
},
{
"idx": 72,
"version": "7",
"when": 1775652883157,
"tag": "0072_jittery_steve_rogers",
"breakpoints": true
}
]
}