The first time a Scum list won a championship, Ryan Fleming used a 3 jump master list, at the HOTH Open 2016, first of the 8 System Series X-Wing Tournaments.

From FFG:
Eight Nations, Eight Tournaments:
The X-Wing System Open Series is the first international tournament for X-Wing, held in eight distinct regions around the world. Each region will host a massive tournament that invites players of all skill levels to battle for control of an iconic Star Wars™ planet! Check the schedule below for a full list of tournaments, dates, times, and more information.