Batting at first drop, O’Brien has been the WACA league’s best batsman averaging an intimidating 58.58 per match.
The team captain’s 703 runs far outclass the league’s next best individual total, which stands at 493.
And with Joondalup a strong chance to make the grand final, the right hander could amass 1000 runs from his past two seasons.
The teenager needs 144 runs to complete the milestone, a solid possibility if the Centurions play three finals games.
O’Brien’s improvement has been immense this season, having made just 153 runs in 2012-13.
Joondalup president Max Goldenberg praised the young batsman’s talents.
‘He’s by far the best runs scorer in the 17s competition,’ he said.