Andy Murray v Ivan Lendl: who would win, Briton or his coach?
Andy Murray will probably have to get past two greats of the game if he is to win the Australian Open - but he has a legend in his corner.
The Briton could face Roger Federer and Novak Djokovic at Melbourne Park in the next few days and will be looking to coach Ivan Lendl for advice.
Lendl is a former world number one and eight-time Grand Slam champion, renowned for his iron will and military discipline, who started working with Murray a year ago.
So how would the pupil have fared against the master in his pomp?
Murray gave his verdict to BBC Sport in a Q&A: "Depends on the surface. I think on clay he would have beaten me, on grass I think I might have beaten him and on hard courts... it would have been a good match!"
GORAN IVANISEVIC (Croatia) - 2001 Wimbledon champion
Murray v Lendl: "It depends what grass they play on. If they played on grass now, phew - it's a good match, a good contest between those two.
"Definitely on clay, Lendl will kill him, and hard courts would be tough. But the two grasses are totally different kinds of tennis, between then and now. If Lendl had played on the grass they have now, he would definitely have won Wimbledon."
On coach Lendl: "I know Lendl well, we played a lot of times. Unbelievable guy, unbelievable player. He's a funny character, he can talk a lot, and he's a champion. Lendl brought Andy that aggression to just go for it. You can't expect Federer or Djokovic to just miss the ball if you don't push them. Now he's running well, plus he's going for the shots."
MARTINA NAVRATILOVA (US) - 18-time Grand Slam champion
Murray v Lendl: "I agree with Andy. Ivan didn't really have a weakness. He used the slice more than Andy, but I think Ivan had a bigger serve, better second serve and bigger forehand. But Andy has a bigger backhand. Movement wise, pretty close. Stamina is a tie. Mentally, I would give an edge to Ivan, still, but yeah, it would be a long match and I think they would come out pretty even."
On coach Lendl: "People were asking about Andy picking Lendl because he's never coached anybody - Lendl's a champion and he would definitely make an attitude adjustment with Andy. The results were immediate and I'm not surprised at all. Impressed, but not surprised."
WAYNE FERREIRA (SA) - former world number six
Murray v Lendl: "Both of them were fantastic players. Ivan, at this stage as we look at it, has much better results and because of that I would say he would win. He was quite dominant at one stage. But they would have a hell of a battle because both of them play similar games to a certain degree. They would be out there a long time and it would be fun to watch."
On Lendl: "I think Ivan would have won Wimbledon if the conditions were as they are today. He unfortunately came at a time when the courts didn't suit him, but if he played today with the same guys he had back then, he would have won Wimbledon a lot of times."
MARK WOODFORDE (Aus) - 12-time Grand Slam doubles champion
Murray v Lendl: "Not a bad assessment from Andy. Lendl always had that phobia on grass, and I don't think today's advancement in technology would have erased any of the doubts. I'm curious about the clay-court result because I still believe Andy has such diversity in his game, it's not out of the question for him to win a French Open. On hard courts, maybe Ivan given his results at the US Open and here in Australia as well."
On Lendl: "He was one of the first guys that transcended the fitness side of it. He enjoyed those warm, humid conditions over in Flushing Meadows, much like we can have in Melbourne. You knew there was always one person that it wasn't going to detract from their performance, and that was Ivan."
FABRICE SANTORO (Fra) - two-time Australian Open doubles champion
Murray v Lendl: "Andy is probably right, he will win on grass for sure but it's tough to compare the generations. If they both play with Lendl's racquets, Lendl will win! Lendl was a great player who worked very hard to be at the top - he was very fit. Probably Lendl would win on clay and, yes, hard courts they would play a long, long match."
PAUL HAARHUIS (Ned) - former doubles world number one
Murray v Lendl: "Andy is beginning to blossom in his career now and there might be many more Grand Slam titles coming, but for now Lendl has eight slams, winning the Australian, US Open, French Open. I think I would have to say Andy would win only one out of four matches between them."
CEDRIC PIOLINE (Fra) - US Open and Wimbledon finalist
Murray v Lendl: "They are baseline players, very strong physically, very good defence - I think it would be a long match! Looking from now, I would say more likely Ivan because he's been number one, he won many Grand Slams and he's finished his career, so we know what he did. But I think Andy has more to come, a lot of good years and I hope for him major titles."
AND THE FINAL WORD… ANDY MURRAY
"He was incredibly consistent, very rarely played a bad match and did everything well - served well, good forehand, passed well, moved well. He improved his volleys a lot towards the end of his career as well to try to win Wimbledon. That was the sort of guy he was.
"He could have won more Grand Slams, for sure. He missed a French Open to prepare better for Wimbledon, and when he started playing the Aussie that was on grass too. If the Aussie was on hard courts, I think he would have won more."