def attack(level, attack_progression):
    """
    Calculate base attack bonus

    level: character_level
    attack_progression: good/bad/poor/fighter/rogue/wizard

    returns a number representing the current base attack value

    """
    if attack_progression in ["good", "fighter"]:
        return int(level)
    elif attack_progression in ["fair", "cleric", "rogue"]:
        return int(level*.75)
    else:
        return int(level/2)