Hugh Godwin: OK, some numbers first. We are anticipating Gatland will pick 37 players, with a 20-17 forwards-backs split. He has said he will take six props – with eight replacements being allowed on the bench – and two fly-halves. He has also said the best players will go, and the game plan comes next. Does that make sense?
David Flatman: Australia are always a very clever team, they are painfully intelligent in the way they prepare. But it doesn't matter if the opposition knows your game plan as long as you're good enough at doing it. What counts are individual moments that outfox people, and you only get a chance at those in the opposition half in good positions.
That is where bringing the best players stands up as an argument. Gatland may decide that the Australian scrum is rubbish, and he can pick a load of mobile guys – Tom Croft or Peter O'Mahony in the second row, for example.
But his past suggests the Lions will play a power game: exhaust the touchlines, work all the way across to one side and then the other. An Australian will have to defend three or four phases coming the same way, so there's a lot of work for an opposition pack to do to get around that breakdown. You want Wallaby backs like Kurtley Beale or Adam Ashley-Cooper making as many tackles as possible.
So it's more likely Gatland will pick bangers in the second row. An airy-fairy tighthead prop who scores 15 tries a year but doesn't like scrummaging, or doesn't fit in with a bulldozing, round-the-corner game plan, won't get picked for this tour.
HG: We'll go position by position shortly, but how about the demands of the tour overall? The Wallabies say they are going to hide 25 players away in a training camp. Doesn't that make the matches before the Tests a bit soft?
DF: Those lead-up games will be tough. The 23-year-old local who plays will view it as bigger than any other occasion in his career. But the Barbarians in Hong Kong first up, that really is a lose-lose for the Lions; what if you get injured in that one, before the tour even starts?
HG: It's just a cash-cow of a match, plus it clashes with the French club final, and I know you're gutted that may rule out one of your favourites, Clermont's big Scotland lock Nathan Hines, although we reckon Gethin Jenkins, the Wales prop, will be released by Toulon. On which subject, let's get into selection, starting with the front row.
DF: If this tour was in South Africa or New Zealand, you would be looking at Paul James for scrummaging grunt. As it is, Cian Healy and Gethin Jenkins are in as looseheads, and we need one more. I'd say Andy Sheridan is above all of them and if you were Australian, who would be the bloke you'd least want to scrummage against? Sherry.
HG: But we think he's out because of the French clash, so we need one more loosehead and three tightheads.
DF: Scotland's Ryan Grant does a fair imitation of Healy, but if Alex Corbisiero is fit, he offers more. On the tighthead, Adam Jones and Dan Cole are certainties, and "Corbs" can play there if needed.
So it's one from Mike Ross, Euan Murray and David Wilson. The thin Scottish representation overall may get Murray the nod. But I have played against all of them and on pure form Wilson is the best of the lot.
HG: We both like Joe Launchbury, but we suspect that he has fallen just short because of England's poor showing in the last Six Nations match against Wales.
DF: It's easy to say, that because of that Cardiff game, you should pick all the Welsh blokes and none from England. Until that match England were a young team doing brilliantly, they had legendary status at their feet. But that game had 50 times the pressure of any other, including the All Blacks, and if you were Gatland you would ask: "How did they deal with that pressure?"
HG: But you are picking Wilson… and it looks like our England contingent may be bigger than Gatland's.
On to the three hookers, and we both have Rory Best as our first choice – he's short enough to counter the Aussies however low they go. He seems to me also to be an ideal tourist: a solid character and excellent player in one.
DF: But the number one thing is to be respected for your primary job, however good a bloke you are. Best's tackle-count is massive, his carry-count is massive. The axis of Tom Youngs and Dan Cole struggled in the scrum for England against the Australians last autumn, but I am going for Youngs and Wales's Richard Hibbard as the other two hookers.
HG: Youngs could be brilliant as a second-half substitute.
DF: Oh, he'd been painful off the bench, painful.
HG: Second rows: in 2009 they took five but we think they will nick a place here to account for the sixth prop. This time last year Richie Gray was in everyone's squad – but the Lions didn't go last year.
DF: No, and he's not going now. Launchbury gets hands on the ball, makes lots of yards, plays at a high tempo. I don't think they'll pick Jim Hamilton, but for me he's a nasty so-and-so who would dominate midweek games and be a spiritual leader. But Alun Wyn Jones and Paul O'Connell are nailed on for the trip.
Geoff Parling? Is he brutally powerful enough? He can certainly assist O'Connell in running the line-outs. If Hines is out, then Ian Evans of Wales gets the fourth spot, for a good balance.
HG: We'll get back to the back row as it is going to take the most debate. Scrum-halves: the whisper is that Mike Phillips and Ben Youngs are on the plane, with Danny Care or Conor Murray to join them, though I know some pundits fancy Scotland's Greig Laidlaw for his versatility.
DF: Danny is tearing it up, he's flying, and Murray is not in the same league. You can carp about Danny's style but he can stand and pass if you need him to.
HG: On to the glamour boys at fly-half – all two of them. Can we see past Jonny Sexton and Owen Farrell?
DF: We both have question marks about Farrell's pure ability, the range of what he can do. But if you need someone to kick points and dominate and say "this is what we're doing", he's almost the first choice in the world, mentally. He has unbelievable confidence. Jonny Wilkinson was never as confident as that; Jonny was always anxious before games, and that's what made him brilliant. You wonder if Farrell has ever been nervous in his life.
HG: For me, Jonny never played better than on the 2001 Lions tour. Maybe this is Farrell's time. A little further out, we aren't going to argue on four of our five centres: Jamie Roberts and Manu Tuilagi making dents, along with Brian O'Driscoll and Jonathan Davies?
DF: You need ball-players who are physical enough to live up to the Gatland game plan but also wise enough to leave it behind and break from it. O'Driscoll is bloody physical and he's magic; he's got to go.
HG: If he can stand, O'Driscoll's on the plane. Which reminds me that some top tourists in the past haven't made the starting squad but got called up later: like Tom Croft in 2009, Ryan Jones in 2005.
DF: And Martin Corry in 2001. But it's the starting 37 we need now. The fifth centre could be a utility man, and I'd be happy with Keith Earls, if he's fit. I have seen James Hook for Perpignan recently and he was absolute class. Billy Twelvetrees and Brad Barritt have their different merits.
HG: In the back three we like Leigh Halfpenny as a full-back and a wing, leaving Rob Kearney and Stuart Hogg as straight full-backs.
DF: Yes, Hogg is a brilliant attacker and I think four wings plus Halfpenny is enough. I reckon Chris Ashton has played himself out of the trip, George North and Alex Cuthbert of Wales will go, and Tommy Bowe and Simon Zebo should be with them.
Zebo: what a talent. I can see him in the Test team, scoring two tries and winning a series.
HG: No wing is more exciting in attack than Christian Wade, but the jump from club rugby to a Test with Australia could be just too much.
And so to the back row. We've got a shortlist that's as long as Jim Hamilton's arm.
DF: I would take Nick Easter as one of the two No 8s, and leave Jamie Heaslip out. But Toby Faletau has a lot going for him. And Ben Morgan blasting off the base could be a wrecking ball. As for flankers, well there's Kelly Brown, Tom Wood, Peter O'Mahony.
HG: Put it this way: if the first Test was tomorrow, who would be your back row?
DF: I'd pick Tom Croft at six, Sam Warburton, our captain, at seven backed up by Justin Tipuric and Johnnie Beattie at eight. But I don't think Beattie will go. Steve Ferris and Dan Lydiate are great blindsides but Ferris is injured.
HG: And Lydiate only came back recently. Come to think of it, a few players started playing again in April? Funny that! I think Lydiate is a Gatland man. But what about Sean O'Brien, an explosive player who covers the whole back row?
DF: And then there's Chris Robshaw. You know, Robshaw could be the perfect midweek player. You've got a whole team each week not involved in the big game and they need organising. Imagine the amount of work Robshaw w ould do so that other players didn't have to. What a tourist he would be.
HG: OK, the England captain makes it as our fifth flanker with Warburton, Tipuric, Lydiate and Croft.
DF: I just wish we had room for a few more left-field bolters, even if Gatland is said to have ruled them out. How about a fly-half footballer like an Ian Madigan? And do they recognise how good a ball-player Kyle Eastmond is? Maybe he's one of those who will have to wait for 2017.