Leaderboards

Leaderboards with Sorted Sets

Leaderboards are one of the most popular Redis use cases. Sorted sets make ranking operations trivially efficient — O(log N) for most operations, regardless of the number of players.

Building a Leaderboard

ZADD game:scores 1200 "Charlie" 1000 "Alice" 750 "Bob" 500 "Dave"

Get Top N Players

ZREVRANGE returns members in descending score order:

ZREVRANGE game:scores 0 2 WITHSCORES    -- top 3

Output:

1) "Charlie"
2) "1200"
3) "Alice"
4) "1000"
5) "Bob"
6) "750"

Get a Player's Rank

ZREVRANK gives 0-based rank (0 = first place):

ZREVRANK game:scores "Alice"    -- 1 (second place)
ZREVRANK game:scores "Dave"     -- 3 (last place)

Get a Player's Score

ZSCORE game:scores "Alice"    -- "1000"

Update a Score

ZINCRBY atomically adds to a score:

ZINCRBY game:scores 300 "Bob"    -- Bob's score becomes 1050
ZREVRANK game:scores "Bob"       -- now rank 2

Players in a Score Range

ZRANGEBYSCORE game:scores 800 1100 WITHSCORES    -- scores 800-1100
ZRANGEBYSCORE game:scores -inf +inf              -- everyone

Real-Time Leaderboard Pattern

# Player completes a level — add to their score
ZINCRBY leaderboard:daily 500 "user:42"

# Refresh player's rank display
ZREVRANK leaderboard:daily "user:42"
ZSCORE leaderboard:daily "user:42"

# Get top 10
ZREVRANGE leaderboard:daily 0 9 WITHSCORES

Multiple Leaderboards

Redis makes it trivial to maintain leaderboards at different scopes:

ZINCRBY leaderboard:daily 100 "alice"
ZINCRBY leaderboard:weekly 100 "alice"
ZINCRBY leaderboard:alltime 100 "alice"

Your Task

Build a game leaderboard with four players: Alice at 950, Bob at 1100, Charlie at 800, Dave at 1050. Get the top 3 players with their scores using ZREVRANGE.