It is a sign of the contrasting fortunes of the two north London clubs that tomorrow night Arsene Wenger will lock horns with a ninth Tottenham manager since arriving at Arsenal.

The Frenchman joined the Gunners 12 years ago at a time when Spurs were relatively stable under Gerry Francis but since then the managerial merry-go-round has spun feverishly at White Hart Lane, culminating in Harry Redknapp's appointment on Saturday.

Anyone seeking to explain why Arsenal have held the upper hand over their great rivals in modern times must start with the sitatution in the two dugouts.

The most ardent Spurs fans could argue that their team is closing the gap, winning the Carling Cup this year, while Arsenal have not won a trophy since lifting the FA Cup in 2005.

But overall, in Wenger's 12 seasons at the helm, Arsenal can boast three Premier League titles and four FA Cups, doing the Double in 1998 and 2002, and also reaching the Champions League final in 2006 and the UEFA Cup final six years earlier.

Spurs, by comparison, have won two League Cups, the first under former Arsenal boss George Graham and then Juande Ramos this February, during that period. They have never played in the Champions League.

The Gunners have also been dominant in derby matches, as Wenger has been beaten only twice in 29 matches, 2-1 by Graham's team in November 1999, and 5-1 by Ramos' men in the second leg of last season's Carling Cup semi-final.

Francis, 56, who is now working as a coach for Stoke City, believes that being forced to watch Arsenal's successes from such close proximity has influenced decision-making at Spurs.

He said: "If a club is desperate to win and do well, they do not show so much patience, whereas if you are successful, there are not so many changes.

"The north London derby is important to both clubs, but more so to Tottenham. They have not been able to win things regularly, so they want to put one over on Arsenal.

"It does not help Spurs' situation if Arsenal are winning at home and doing well in Europe, because it creates extra pressure.

"It is similar to the situation in Manchester, with United and City. Ask City fans what it is like. The only chance you get to put one over on your rival is in the derby games."

Francis guided Spurs to seventh in 1995, eighth in 1996, and tenth in 1997, before resigning after a poor start to the 1997/98 season.

On the added pressures now facing former Portsmouth boss Redknapp, he added: "Look at Martin Jol. He finished in fifth place in the Premier League in 2006 and 2007, and if Harry got two fifth-placed finishes in a row, he would be doing very well - but Martin Jol still lost his job.

"At a club like Portsmouth, you can have a hiccup or a bad start, and there is not the same pressure on you, so you can get out of it.

"But at Tottenham, you are always under the cosh. Everything is magnified. It is a great opportunity for Harry, but he will find a huge difference in the expectation levels between Spurs and Portsmouth."

Spurs are also falling behind Arsenal off the pitch, according to football finance expert Professor Tom Cannon, of the University of Liverpool.

Cannon said: "In this market place, Spurs are losing massively against their big rivals Arsenal in north London.

"Not so long ago, Tottenham were considered roughly the same size as Arsenal, but now Arsenal are a club worth about £770million, while Spurs would be worth about £200m."

But George Graham, who managed Arsenal from 1986 until 1995 before taking charge of Spurs from 1998 until 2001, believes Redknapp is the perfect man to drag Spurs back towards the top of the English game.

He added: "Harry is the ideal choice for Spurs. He has proved that, and it is great to see a British manager getting a top job."