A bigger season
The seventh Big Bash League was the first of two consecutive expansions. The league stage grew from eight matches a side to ten, giving 40 league games and 43 in all, and the season stretched from 19 December 2017 to 4 February 2018. Total attendance was 1,140,835. Perth Scorchers moved their home matches from the WACA Ground to the new Optus Stadium, and several fixtures, including the final, were staged as double-headers with the Women's Big Bash League.
Short's summer
D'Arcy Short had made his Twenty20 debut for Hobart Hurricanes only the previous season. In 2017-18 he made 572 runs, more than anyone had made in a Big Bash League season, at a strike rate above 140. The innings that defined it was 122 not out against Adelaide Strikers, then the highest individual score in the competition's history, and he added scores of 97 and 96. He was named player of the tournament, and he also bowled left-arm wrist spin usefully enough to be picked for Australia during the same summer.
Adelaide Strikers had signed Rashid Khan, who took 18 wickets in his first season in the competition and gave them control of the middle overs that no other side could match. Kane Richardson of Melbourne Renegades also took 18.
The league stage
Perth Scorchers won eight of ten to finish first, Adelaide Strikers seven, Melbourne Renegades six and Hobart Hurricanes five. Melbourne Stars, who had been in three of the previous six finals, won two and finished last.
Semi-finals
Hobart went to Optus Stadium on 1 February, made 210 for 4 and bowled the defending champions out for 139. Matthew Wade took the match award. The following night Adelaide Strikers defended 178 against Melbourne Renegades at Adelaide Oval, winning by a single run when the Renegades finished on 177 for 4. Travis Head was named player of the match.
The final
Adelaide Oval, 4 February. Adelaide Strikers made 202 for 2, Jake Weatherald scoring 115 and putting on a large opening stand with Head. Hobart, chasing for the second final in five seasons, were held to 177 for 5. Weatherald was named player of the match, Rashid Khan bowled his four overs for little, and Adelaide won a first title at the seventh attempt. Hobart, beaten finalists in 2013-14 and now again, remained the only original club without one.
What followed
The expansion continued the next summer, when the league stage doubled to fourteen matches a side and the season ran to the middle of February. The 2017-18 season was, in retrospect, the last of the competition's compact era: 43 matches, six weeks, and a straightforward four-team knockout.