DERBY DAYS/TORONTO MAPLE LEAFS v MONTREAL CANADIENS:Maple Leafs Canadiens Saturday in Toronto & Saturday, April 5th, in Montreal

RIVALRIES HAVE have developed for many reasons - on-field incidents, off-field incidents, cultural, religious, linguistic and national differences, familiarity, geographic reasons, etc.

Few though can point to "all of the above". Ice hockey's biggest showdown is not about sport. It is where Canada's two cultures - the French and the English - came to do battle.

In the early years of the National Hockey League, the competition was limited to central Canada. By the 1920s, though, the NHL was rapidly expanding as far south as Chicago, New York and Pittsburgh. The rapid growth was almost as fast as the sudden collapse - with first the Great Depression, and then the second World War, blamed for many teams going to the wall.

The NHL retreated to just six teams - the Montreal Canadiens, Toronto Maple Leafs, Detroit Red Wings, Chicago Black Hawks, Boston Bruins, and New York Rangers - and that's how it remained through the 1940s, '50s and '60s.

Even solely on the basis of familiarity breeding contempt, rivalries were inevitable. Still, when Canada's largest cities clashed it always had number one billing.

Since the 18th century tensions in Canada have been between the English-speaking and French-speaking natives. When the (English) Toronto Maple Leafs and (French) Montreal Canadiens came along, the ice did nothing to lower the temperature.

By the 1960s, the rivalry was front page news in North America, and the two teams were dominating the NHL - winning four Stanley Cup finals each during the eight seasons from 1961-62 to 1968-69.

The 1967 decider - in the 50th season of the NHL - was a defining moment in the history of the rivalry.

It was to be the last season of the "Original Six", with six more teams ready to enter the following season, and the Canadiens began the best-of-seven finals series hot favourites to win their third Stanley Cup in a row.

The Maple Leafs were a unusual mix of players in their first season and several players who were in their early 40s. Despite losing the first game 6-2, Toronto stormed back to win four of the next five games to claim their 13th Stanley Cup.

However, little did the celebrating fans from Toronto know that over 40 years later the Maple Leafs would not have even reached another decider, whereas the Canadiens would make another 11 finals appearances, winning the title as recently as 1993.

By then, the rivalry had cooled somewhat mainly because Toronto were now in the Western Conference and Montreal in the Eastern section.

But, in 1998, the teams were back in the same conference, and it was soon evident absence had not made the heart grow fonder. The final game of last season's regular season was perhaps the most important battle between the two rivals in decades. The Montreal Canadiens were in eighth place, with the top eight qualifying for the play-offs. The Maple Leafs were one point behind, and emerged victorious - denying Montreal a post-season.

However, with Montreal already looking forward to this season's Stanley Cup play-offs, time is running out for Toronto. The game in Montreal on Saturday week will be the final game of the regular season, and unless the Maple Leafs pull off two big results over the next two weekends, it will be another short season for the long-suffering Toronto fans.

Regardless, for two more games at least, the stakes will be high, the hits big and the atmosphere electric.