Not Updated For Current Season
With this build sequence in my last three matches I have gone 10-0, 12-1, and 17-3. Once you get to full stacks with attack speed you have enough life steal to kill anyone in a 1v1 situation. Also In 2 of those matches listed I was triple teamed at level 18 and whipped out all 3 players without dieing causing the other team to forfeit. Jax gets so much attack speed that he is also amazing at turret killing. Give this build a try.
My strategy in a 3v3 is to solo the middle lane until about level 10. Then I go back and forth between jungling and minion killing until level 18. That is when I really start worrying about getting turrets and killing players on other team.