When Earvin “Magic” Johnson made his NBA Finals debut with the Los Angeles Lakers in 1980, the games were televised on “tape delay” by the American networks, rather than shown live. By the time Johnson and Larry Bird, of the Boston Celtics, had finished restructuring the American sporting landscape and re-establishing their teams' decades-long rivalry, the sport would not be the same.

Fast-forward nearly three decades and for the first time in 21 years - and the tenth time in history for the franchises - the Celtics and the Lakers are in the NBA Finals and, as was the case on the first occasion that Johnson and Bird squared off in a Finals, in 1984, the league awaits a much-needed boost from the pairing.

Last season, the NBA's viewing figures slumped to a rating of 6.2 (about seven million households) as the San Antonio Spurs swept aside the Cleveland Cavaliers in four games, the lowest viewing figures in a quarter of a century. Analysts predict that this year's Finals will attract about double those figures, a respectable return for ABC, ESPN and TNT, which renewed their television deal last year through to 2016 at a cost of $7.6billion (about £3.8million) and who will be charging between $350,000 and $450,000 for a 30-second advertisement during broadcasts.

But this season's NBA Finals, which open in Boston today with the first match in a best-of-seven series, are about more than business arithmetic. To basketball fans of all ages the mention of “Celtics and Lakers” in the same sentence is guaranteed to bear the same gravitas and impact as do “Manchester United and Liverpool” or “Real Madrid and Barcelona” to the modern football fan.

With Bill Russell, the most successful and arguably best ever basketball player, in their ranks, the Celtics won all six of the Finals meetings between the clubs as they dominated the 1960s. Johnson and Bird took the rivalry to a new level in the 1980s, Johnson winning two out of the three Finals in which the teams met, at a time when the NBA was struggling to establish itself in mainstream America.

“Back then a lot of Finals games were shown tape delayed,” Bird said yesterday. “David Stern took over [as commissioner] in '84 and we got into prime time. Both our teams were playing at a high level, then Michael Jordan came into the league. We had a bunch of talent coming in in the mid-Eighties. They were young, but their games were developing and they had a lot of star power and they took the league to another level.”

While the Lakers have maintained a decent level of consistency - winning championships in consecutive seasons from 2000 to 2002 - the Celtics had fallen upon hard times until last summer's signing of Kevin Garnett from the Minnesota Timberwolves. Yet, even though many of the present Lakers and Celtics players were in short trousers the previous time the teams met in the play-offs, Johnson has no doubt that they will appreciate the rekindling of an old, often rancorous rivalry.

“When that ball goes up [for the tip-off], they'll understand,” Johnson said. “They might not understand what we went through, but they will have their own rivalry because this is for all the marbles, everything. It doesn't matter whether they understand our rivalry or not. They will create their own rivalry, starting Thursday.”

Paul Pierce, who grew up in Los Angeles a Lakers fan but is a key Celtics player, and Luke Walton, of the Lakers, who was raised a Celtic because his father, Bill, played for Boston, will need no explanation of the historical context of the 2008 Finals.

“The good thing for me is the league is back to selling franchises, not individuals,” Johnson said. “It's great. We're talking about the Lakers and Celtics, not individuals.” Nevertheless, one individual - the peerless Kobe Bryant, who has those three championships at the start of the decade to his name at the age of 29 - will probably separate the teams.

“The one thing I see could hurt the Celtics is Kobe has been there before,” Bird said. “He's won three championships. He'll be a steadying force to the rest of the players. They look up to him so much and when things get tough, he could be the one to pull them through.”