import { type JudgeLLM } from './adapters';
export type PairwiseWinner = 'a' | 'b' | 'tie';
export type PairwiseResult = {
    ok: true;
    winner: PairwiseWinner;
    rationale: string;
    cacheHit: boolean;
    costUsd: number;
    latencyMs: number;
} | {
    ok: false;
    error: string;
};
export type ComparePairInput = {
    taskType: string;
    input: string;
    outputA: string;
    outputB: string;
    variantIdA?: string | null;
    variantIdB?: string | null;
    judgeLLM?: JudgeLLM;
};
export declare function comparePair(params: ComparePairInput): Promise<PairwiseResult>;
export declare function updateElo(ratingA: number, ratingB: number, outcome: number, k?: number): {
    newA: number;
    newB: number;
};
export type RecordMatchInput = {
    taskType: string;
    variantIdA: string;
    variantIdB: string;
    winner: PairwiseWinner;
    input?: string;
    k?: number;
};
export type MatchResult = {
    matchId: string;
    eloA: number;
    eloB: number;
};
export declare function recordPairwiseMatch(params: RecordMatchInput): MatchResult;
export type BradleyTerryResult = Record<string, number>;
export declare function fitBradleyTerry(matches: Array<{
    a: string;
    b: string;
    winner: PairwiseWinner;
}>, opts?: {
    iterations?: number;
    tolerance?: number;
}): BradleyTerryResult;