This achievement is earned by climbing to the top of the leaderboards in an event. Events are unlocked by doing sponsor challenges, which later open up events to compete against a pro and the leaderboards. To beat the leader, you must take the leading score and multiply it by three. That total is what you must beat in all three rounds combined. You do not have to get a high score in every round, you just have to make sure that your score is higher than the leader's score multiplied by three.
50,000 x 3 = 150,000,
3/150,000 = 50,000 (Average)
The leaderboards are reset weekly on Sundays at 4 AM GMT.