def elo_ratings(vote_pairs, k_factor=32,
                initial_rating=1000):
    # Initialize all models with the same base rating
    ratings = {
        model: initial_rating
        for pair in vote_pairs
        for model in pair
    }

    # Update ratings after each match
    for winner, loser in vote_pairs:

        # Expected score for the current winner
        expected_winner = 1.0 / (
            1.0 + 10 ** (
                (ratings[loser] - ratings[winner])
                / 400.0
            )
        )

        # k_factor determines sensitivity of updates
        ratings[winner] = (
            ratings[winner]
            + k_factor * (1 - expected_winner)
        )
        ratings[loser] = (
            ratings[loser]
            + k_factor * (0 - (1 - expected_winner))
        )

    return ratings