Rory Best has backed Andy Farrell to thrive as Ireland head coach, when he replaces Joe Schmidt after next year's World Cup.

Current Ireland boss Schmidt will step down after the tournament to focus on his family, with assistant coach Farrell then taking the top job.

Former dual-code international Farrell has hit back from losing his England coaching job after the 2015 World Cup to star in back-room roles for both Ireland and the British and Irish Lions.

The 43-year-old will be breaching new territory as a head coach, but Ireland captain Best insists Farrell will take the transition in his stride.

Asked whether Farrell will handle the switch in approach from assistant to overall boss, Best said: "I don't see any reason at all why not, I think he did a lot more in England than he does with us.

"From what I gather he took a bit of the attack there. Here he takes the defence and Joe (Schmidt) the attack. Andy is a very smart rugby player, he was when he played and he is as a coach.

"When you get somebody like that and you put them into an environment like we've been in for the last couple of years, he's going to learn a lot from Joe Schmidt.

"Joe's biggest legacy is going to be the coaches he leaves behind.

"Once the trophies have all been packed up and the dust has settled on them, it will be the coaches, the likes of Andy Farrell, Simon Easterby, Richie Murphy, some of the players he's coached too, you see it with Leo Cullen now; that is going to be his lasting legacy."

Kiwi boss Schmidt has dragged Ireland from eighth to second in the world rankings in five years at the helm, but now intends to end his coaching career after next year's World Cup.

Ulster and Lions hooker Best has risen to captain Ireland under Schmidt, succeeding Paul O'Connell as skipper.

The 36-year-old has led Ireland to a historic third Six Nations Grand Slam and the nation's first two victories over back-to-back world champions New Zealand.

Farrell will face a tall order in building on Schmidt's excellence, but Best believes the former Wigan rugby league star has all the right attributes for success.

"I think probably the thing that Faz (Farrell) does better than any other coach, he makes it feel personal for him," said Best.

"He really buys into it. He stands in front of you, he's a big frame, and he speaks, and it's impossible not to like him.

"But when he talks about defence, he makes you want to go and defend. If he talks about any aspect of the game, you just want to buy into it.

"One of the things about being a head coach that Joe got, yes it's about all the technicalities, but a lot of the time it's about being a good man-manager, being liked and knowing how to interact with the players.

"And probably there's nobody better than Faz for that. Whenever he asks you to do something, he has so much passion about it.

"It's actually sometimes a bit surreal to be coached by someone that you watched on Grandstand running around for Wigan when they dominated absolutely everything.

"He was their key figure; he was their go-to man. He's never happy with our defence, even though New Zealand didn't score a try against us, he was still saying we can do this better, we can do that better.

"He is driven. It's all about perfection, it's all about being driven and trying to be better.

"And if somebody gets in the way of us achieving that, we'll go past them, over them, whatever it takes."