There have been three regular season sweeps in the history of the rivalry. The Flames swept the six-game series in 2009–10 and the five-game series in 2014–15, while the Oilers swept the four-game series in 2016–17. The Flames’ sweep of the Oilers in 2009–10 was significant in the sense that they tied the rivalry’s win-loss-tie overall regular season and playoff series (since the team’s move to Calgary) on December 28, 2009. They then took the overall series lead with their victory over the Oilers three days later, and they have not relinquished it since (as of the end of the 2019–20 season). The Oilers had previously led the series since October 20, 1981. The aforementioned 2009–10 season also marked the first-ever trade between the two rivals, with Edmonton's Steve Staios being traded for Calgary's Aaron Johnson on March 3, 2010.