What must go right for the Premier League's title contenders?
The top Premier League clubs have already been busy making signings ahead of the new season, but every single one of them has a key issue they must hope goes their way in order to contend for the title.
ARSENAL: Some creativity must be found in midfield
It seems rather curious to say that Arsenal, for so long the side most derided as a team full of lightweight yet aesthetically pleasing tippy-tappers, could really do with a creative presence in central midfield.
For a while, Santi Cazorla seemed to have cracked the problem, but since his significant ankle injury last October, Arsenal have lacked someone who can feed the more dynamic attacking talents ahead of him. With Cazorla still slowly recovering (with one perhaps slightly hysterical report suggesting that he would never play for the club again), an alternative needs to be found, and it's tricky to see where it might come from in the current ranks. None of Francis Coquelin, Mohamed Elneny, Granit Xhaka, Aaron Ramsey or Alex Oxlade-Chamberlain really fit the bill, even if they bring their own qualities to the table.
The more optimistic Gooners might point to the return of Jack Wilshere, but it has been almost a decade since his first-team debut, and we're still waiting for him to fulfill his potential. Wenger must find creativity of some description from somewhere, or else it might not matter how well Alexandre Lacazette combines with Mesut Ozil and Alexis Sanchez, if there's nobody to give them the ball.
CHELSEA: The centre-forward issue must be solved
You get the impression that where possible, avoiding making Antonio Conte angry is a decent survival tactic. Whoever told him that Romelu Lukaku was off to Manchester United rather than Chelsea probably did so while wearing protective gear of some kind.
Conte took a reasonably significant gamble in informing Diego Costa that he was no longer required way before any replacement was secured because while there are alternatives to last season's top-scorer out there, they're relatively limited. The only real "in-house" option, Michy Batshuayi, still seems unpolished. Alvaro Morata seems to be the new favourite to take the role, but he's a rather different kind of striker to both Costa and Lukaku. Therefore, how Chelsea's plans will change if he is the man brought in is something to ponder.
Conte managed to fashion a title-winning team from what he had available last season, but this time around, he needs the right personnel.
EVERTON: Can enough of their gambles pay off?
Conventional wisdom states that significant overhauls of football teams are to be broadly avoided. The number of moving parts to a side generally mean that evolution is preferable to revolution, but while Everton have received plenty of praise for their transfers so far this summer, they have taken a number of relatively significant gambles.
Michael Keane looks the safest bet, an established centre-back taking a manageable step up, but elsewhere, there are bigger question marks. Jordan Pickford certainly looks like the real thing, but he has barely had a season in the Premier League. Sandro Ramirez is a little more experienced but likewise has only one term as a starter to his name. Players from the Eredivisie can sink or swim, so Davy Klaassen isn't a banker, and everyone knows the potential problems with Wayne Rooney.
On top of all this is the potential for these new arrivals to stunt the progress of the hugely promising youngsters, such as Tom Davies, Ademola Lookman and Dominic Calvert-Lewin. An interesting season lies ahead for Ronald Koeman.
LIVERPOOL: Who is holding it together in defensive midfield?
Liverpool's attack for the coming season looks to be in fine shape. Jurgen Klopp's biggest problem there is option blindness, given the number of forwards he has at his disposal. The defence could be an issue, but Liverpool at least seem to be doing something about it, even if Virgil van Dijk isn't the man who'll arrive. But there seems to be less movement on a new defensive midfielder, which suggests that Klopp regards Jordan Henderson as not only his best but also possibly his only option in that position.
Henderson is a fine footballer and did reasonably well in that role last season before an injury curtailed his season, but it does seem to be a relatively significant gamble to place all faith in his succeeding there.
MAN CITY: Which goalkeeper should they back?
At the time of writing, it isn't entirely certain who Manchester City's first-choice No.1 will be. It probably won't be Joe Hart, and it probably shouldn't be Claudio Bravo, which leaves new signing Ederson. Purchased at some expense from Benfica in the summer, he is very promising but still just 23, young indeed for a goalkeeper.
Ederson has to be many things, firstly good enough with his feet to satisfy Pep Guardiola's dictum on distribution but also good enough at the more straightforward aspects of goalkeeping to, well, not be another Claudio Bravo. Ederson has not yet made a senior international appearance and has only one season as a first-choice keeper in a top-ranked team. The pressure on him, and indeed Guardiola, to be good enough will be strong.
MAN UNITED: Paul Pogba being Paul Pogba
It's perhaps a little reductive to say that for the amount of money Manchester United have spent the past couple of summers, they need to significantly challenge for the Premier League title this season. But it is broadly true, and the addition of Romelu Lukaku isn't going to reduce that pressure at all.
One of the reasons for purchasing Lukaku is that he might perhaps link up well with his good friend Paul Pogba. That's arguably Jose Mourinho's biggest task this season: to get the best from a midfielder who wasn't as bad as some might have you believe last season but was still not quite the match-winner he can be.
That was sometimes his fault, sometimes Mourinho's and sometimes the team's, but probably the key will be getting the best from their record signing, whether that's from his partnership with Lukaku or in constructing a midfield around him that will enhance his best qualities.
TOTTENHAM: Can they stay healthy?
Fitness is of course an important issue for any team, but for Tottenham it's more important than most. Last season, in games in which their key men were absent -- particularly against the very best -- their relative lack of depth was exposed and showed that beyond their best 13 or 14 players, there was a drop-off in quality. They are operating under straitened circumstances, with the building of their new stadium meaning that they cannot afford to spend especially lavishly, and this summer seems like it's going to be a relatively quiet one for them.
If arrivals are more of the Moussa Sissoko level than anyone who could challenge their established starters, then Mauricio Pochettino needs to hope that the likes of Dele Alli, Toby Alderweireld, Harry Kane and Christian Eriksen avoid major injuries if his team are to challenge for the title again.
Nick Miller is a writer for ESPN FC, covering Premier League and European football. Follow him on Twitter @NickMiller79.