simple shogi elo calculator based on http://fesashogi.eu/index.php?mid=5&listid=elosystem

fesa-elo.py

K_FACTORS = (
    (720, 40),
    (1040, 36),
    (1280, 32),
    (1560, 28),
    (1920, 24),
    (2240, 20),
    (9999, 16),
)


def get_elo(tr, games, results):
    for r, kr in K_FACTORS:
        if tr < r:
            k = kr
            break
    else:
        raise ValueError("Invalid rating")
    change = 0
    for or_, res in results:
        ev = 1 / (1 + 10**((or_ - tr) / 400))
        change += k * max(res - ev, (or_ - tr) / 160 if res == 1 else -ev)
        if games < 100:
            change += max(1800 - tr, 0) / 200
    return round(tr + change)


def main():
    myelo = int(input("Player Elo: "))
    mygames = int(input("Player games: "))
    results = []
    try:
        while True:
            oppelo = int(input("Opponent Elo: "))
            result = int(input("Result: "))
            results.append((oppelo, result))
    except ValueError:
        pass
    print("New Elo: {}".format(get_elo(myelo, mygames, results)))


if __name__ == '__main__':
    main()

ported to JS for this html web page https://amshogi.github.io/rangos/rango-calc.html

👍