simulation/win_probability.py

from __future__ import annotations


def win_probability(score_diff: int, inning: int, is_home_batting: bool) -> float:
    """
    Simple explainable baseline for live WP.
    """
    base = 0.50 + (score_diff * 0.065)
    inning_pressure = min(0.20, max(0.0, (inning - 1) * 0.02))
    home_edge = 0.015 if is_home_batting else -0.015

    wp = base + inning_pressure + home_edge
    return max(0.01, min(0.99, wp))