Test match rugby often comes down to the smallest of margins - a knock-on here, a conversion hitting the post there - but where will Saturday's first test really be won and lost?
The set piece
Tuesday's disaster against the Brumbies proved that getting a stable platform in the scrum and at the line-out is of vital importance in any rugby match. The Lions lost eight line-outs that day and simply could not get a foothold in the game.
Alex Corbisiero has been picked ahead of Mako Vunipola for his scrummaging, which could be a canny selection from Warren Gatland as he looks to bully the Australians up front. The man he is up against, Ben Alexander, has a reputation for being great in the loose but a bit shaky in the scrums - ironically, not unlike Vunipola.
At the line-out it will be very close. Australian debutant Ben Mowen is every bit as athletic as the Lions biggest weapon, Tom Croft. Paul O'Connell and Alun-Wyn Jones both have experience running line-outs, and with probably the best operator in this area in the Northern Hemisphere on the bench in the shape of Geoff Parling, the Lions could have an edge.
Will the Lions regret not naming cover for openside flanker on the bench? It certainly heaps the pressure onto captain Sam Warbuton's shoulders, as he is the only recognised player in this position in the entire squad.
It means he will have to take on both Michael Hooper, who starts, and Liam Gill, who is on the bench. Both are accomplished foragers. Warburton will be backed up by Croft and Heaslip, not to mention O'Connell and Tom Youngs, who love to charge into breakdowns, but if he cannot get parity at least with his opposite man it could be a tough afternoon in this area for the Lions.
Any team with Leigh Halfpenny in it is going to have the edge here. He may not have the longest boot in the world, but it is deadly accurate. He has missed just one kick on the tour so far, and with the difference between winning and losing often no greater than the width of a post, the Lions can be confident of the majority of scoring opportunities being converted.
The Australians, for their part, have several options to choose from. James O'Connor used to take their kicks, but as he is starting just just his second test at fly-half it is expected that the goal-kicking responsibilities will be shifted to fullback Berrick Barnes. This will allow O'Connor to focus solely on the playmaking duties.
As if that weren't enough, debutant Christian Leili'ifano has been banging them over for the Brumbies all season, while off the bench Kurtley Beale has a giant boot that will be all too familiar to Welsh fans.
The build-up has been excruciatingly long, but it is now finally time for the Lions to take to the test arena once more. Whether you're Australian, British, Irish or merely a rugby fan one thing is for certain - Saturday will be epic.