Duplicate COUNT when doing JOINS and CONDITIONS along with GROUP BY - mysql

Question

I have the following two tables
games
+--------+-------------+----------------+----------------+
| gameID | challengeID | player1_userID | player2_userID |
+--------+-------------+----------------+----------------+
| 1 | 1 | 1 | 2 |
| 2 | 1 | 1 | 3 |
| 3 | 2 | 1 | 4 |
+--------+-------------+----------------+----------------+
challenges
+-------------+---------+
| challengeID | content |
+-------------+---------+
| 1 | one |
| 2 | two |
| 3 | three |
+-------------+---------+
And I want the output to be as below. Basically, a user (say, userID = 1) wants all challenges' data along with the count of the games played against each challenge and also information on whether that challenge has been played by the requesting user.
output (for userID = 1)
+-------------+---------+---------+---------------------+
| challengeID | content | n_games | played_by_requestor |
+-------------+---------+---------+---------------------+
| 1 | one | 2 | TRUE |
| 2 | two | 1 | TRUE |
| 3 | three | 0 | FALSE |
+-------------+---------+---------+---------------------+
This appeared to be deceptively simple, but I've been trying it for the past 4 hours (it is 1:35am now) and the best I could get to was the code below.
SET #myID = 1;
SELECT
COUNT(g1.challengeID) as n_games,
CASE
WHEN g.gameID IS NULL THEN FALSE ELSE TRUE
END AS played_by_requestor,
c.*
FROM challenges c
LEFT JOIN games g
ON c.challengeID = g.challengeID AND
(player1_userID = #myID or player2_userID = #myID)
LEFT JOIN games g1
ON c.challengeID = g1.challengeID
GROUP BY c.challengeID;
But it gives the wrong result. For requestor userID = 1, this code gives n_games = 4 for challengeID = 1 and also n_games = 1 for challengeID = 2.
SQL Fiddle here
Thanks.

Answer 1

Finally, got it to work !
SET #myID = 3;
SELECT
COUNT(g.challengeID) AS n_games,
CASE
WHEN uC.p_challengeID IS NULL THEN FALSE ELSE TRUE
END AS played_by_requestor,
c.*
FROM challenges c
LEFT JOIN games g
ON (c.challengeID = g.challengeID)
LEFT JOIN
(SELECT g1.challengeID AS p_challengeID
FROM games g1
WHERE (player1_userID = #myID OR player2_userID = #myID)
GROUP BY g1.challengeID) uC
ON c.challengeID = uC.p_challengeID
GROUP BY c.challengeID;
If there is a more elegant solution (e.g. without using two joins on games table), I'll gladly accept it as the answer.