Possibly the aim of bowls and snooker players: to win big (3,3,7)
I believe the answer is:
hit the jackpot
'win big' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for hit the jackpot that I've seen before include "Win top prize" , "Have a great and unexpected success" , "Strike it lucky" , "Win the big prize" , "Achieve lucky success" .)