Former Formula 1 driver Vitantonio Liuzzi believes Red Bull's Christian Horner and Helmut Marko are contrasting personalities who work well together.
Liuzzi was one of Red Bull's first drivers when they joined F1 in 2005 and worked with Horner in the Formula 3000 championship, the equivalent of Formula 2, at Arden. He has always seen great leadership qualities in Horner.
"They are completely different to each other," Liuzzi told RacingNews365.com. "I'm really happy that Horner, sometimes I read in some interviews, said that it [partly] was thanks to me that he started with Red Bull.
"In 2004, I remember when I worked with Arden, Christian Horner was an amazing Team Principal. You can see that he had [a] great point of view in all situations and he was really a machine as the team director.
"When I was talking to Dr. Marko I was always talking really highly about Christian. Marko has an amazing experience as a driver.
"It was a long time ago but he knows in an Austrian way, in a [straightforward] way how a team has to be run. I think they push each other and they did amazing things for the team."
Red Bull won four consecutive world titles with Sebastian Vettel between 2010 and 2013. Liuzzi, who says he still talks to Marko and Horner when he's in the paddock, feels Marko and Horner were key to Red Bull's success in F1 which began with their first victory in 2009.
"I have to say that the first two to three years were not easy for me internally," added Liuzzi. "Not between them but between a lot of people involved in the Red Bull management.
"There were difficulties to deal with each other because everybody wanted to be right compared to the next one. But suddenly in 2009 [Dietrich] Mateschitz decided to give everything to the hands of Marko.
"I think Marko together with Christian were the perfect match to bring the team [together] to win the championship."