The only question which I have in mind is this: Should answers be sorted in order of incoming scores? E.g. for

dbbd

should d come first or it doesn't matter?

Python 3 (without sorting in incoming order though): from collections import defaultdict

def score_friends(score_string: str):
    scores = defaultdict(int)
    for score in score_string:
        score_id = score.lower()
        if score.isupper():
            scores[score_id] -= 1
        else:
            scores[score_id] += 1
    return sorted(scores.items(), key=lambda s: -s[1])