Tottenham manager Andre Villas-Boas has accused former club Chelsea of lacking style and being "invisible" due to numerous managerial changes, despite enjoying a successful past decade.
Villas-Boas is set to return to Stamford Bridge for the first time since he was sacked by the Blues for Wednesday night's crucial Premier League game that could make or break Spurs' Champions League dream.
"In the end, (changing managers) has brought them success and sometimes success is what matters in football, independent of the style," said Villas-Boas.
"I have a different opinion. I think if you don't have a style, it makes you invisible in football. Only teams with style succeed, but in the end, success normally is what matters in modern Europe.
"I mean style of play. When things are attractive. Obviously what is attractive to me is maybe different to the style of football you might find attractive.
"We saw the wonderful team Mauricio (Pochettino) is building at Southampton. The change from Nigel (Adkins) to Mauricio was difficult to take, but the reality is Southampton is not invisible in terms of their football. Their football is absolutely outstanding this season."
Villas-Boas went on to suggest the first Jose Mourinho team at Chelsea was the most dynamic in the club's recent history, but he suggested they failed to build on that image as their focus on silverware did not cater for a long term legacy being created.
"If you remember the (Chelsea) team of 2004 was an absolutely deadly machine of football, but in a different way" he added. "Great counter-attacking football and one of the great teams in the country.
"There are various types of teams, teams built along great creative players and these Chelsea teams have the ingredient to be able to play this type of football."
Spurs need to win at Stamford Bridge for the first time since 1990 to sustain their top four challenge, while Chelsea will all but sealing a Champions League return if they win the London derby against their old foes.