Since the CFL instituted its crossover rule in 1996, 11 teams have qualified for the playoffs in the opposite division.
All of them have come from the west, but there has not been a crossover team in the Grey Cup.
The B.C. Lions will attempt to enter uncharted territory this year as the latest crossover team. They face the host Hamilton Tiger-Cats in the Eastern semi on Sunday, with the winner travelling to Ottawa to meet the Redblacks in the division final next week.
A crossover happens when the fourth-place team in one division finishes with a better record than the third-place team in the other.
Here's a look at how the crossover teams have fared in the playoffs:
1997: B.C. Lions lost to Montreal Alouettes in Eastern semi.
2002: Saskatchewan Roughriders lost to Toronto Argonauts in Eastern semi.
2003: B.C. lost to Toronto in Eastern semi.
2005: Saskatchewan lost to Montreal in Eastern semi.
2008: Edmonton Eskimos beat Winnipeg Blue Bombers in Eastern semi, lost to Montreal in Eastern final.
2009: B.C. lost to Hamilton Tiger-Cats in Eastern semi, lost to Montreal in Eastern final.
2012: Edmonton lost to Toronto in Eastern semi.
2014: B.C. lost to Montreal in Eastern semi.
2016: Edmonton beat Hamilton in Eastern semi, lost to Ottawa Redblacks in Eastern final.
2017: Saskatchewan beat Ottawa in Eastern semi, lost to Toronto in Eastern final.