England start their bid for World Cup glory on Sunday when they face Tonga in their Pool C opener in Sapporo.
What team do you think head coach Eddie Jones should pick?
Is Owen Farrell a fly-half or a centre?
Which two of Maro Itoje, Joe Launchbury, George Kruis and Courtney Lawes make up the second row?
Which combination of Tom Curry, Sam Underhill, Mark Wilson and Lewis Ludlam gives you the right back-row balance?
And do you risk Jack Nowell or Henry Slade after they picked up injuries in the build-up to the tournament?
You can pick your team below, and when you are done have a look below to see which XV rugby union correspondent Chris Jones has gone for...
1. Joe Marler
Mako Vunipola - who worryingly has had a setback in his recovery - is England's starting loose-head prop when fit, but Marler has looked hungry since coming out of international retirement. Ellis Genge to make hay off the bench.
2. Jamie George
Without Dylan Hartley, George has become the man in the number two shirt, having a brilliant season for club and country. Luke Cowan-Dickie is still inexperienced and Jack Singleton is very much travelling as back-up.
3. Kyle Sinckler
Dan Cole's experience and technical nous will be an asset this World Cup, but there is no doubt Sinckler is England's starting tight-head. Part of an England forward pack full of power and dynamism.
4. George Kruis
Kruis has enjoyed a fantastic 2019, allying his lineout expertise with hugely improved physicality.
5. Maro Itoje
Works superbly with Kruis, and provides so much of England's energy both sides of the ball.
6. Mark Wilson
Tempted to play Tom Curry here with Sam Underhill at open-side flanker, but Wilson deserves to be in England's first-choice pack after a strong year. Will provide industry for the first hour before the game opens up.
7. Tom Curry
Not much between him and Underhill at the moment, with Curry's improved ball-carrying just about getting him the nod. Underhill to make an impact off the bench - possibly alongside Curry.
8. Billy Vunipola
England's only specialist number eight in the squad - and, like his brother, a man who can lay claim to being the best in the world. If Billy is injured, England's World Cup hopes may go with him.
9. Ben Youngs
Eddie Jones has curiously made scrum-half an uncompetitive position: if Youngs is fit, he starts. A class act, but has looked a little rusty in the warm-ups. Improved showing against Italy but could still back himself more with ball in hand.
10. George Ford
Whether Ford starts the big knockout games remains up in the air, but his partnership with Farrell will give England the chance to hit the ground running in Japan. A fantastic ball player who ruthlessly picks teams apart when given quick ball.
11. Jonny May
Has become a central figure for England, and has been a stand-out player for the past 12 months. Has worked on both his speed and physicality in the training camps and is a shoo-in.
12. Owen Farrell
With Henry Slade short of fitness and game-time, Farrell switching to 12 seems the sensible option at the start of the tournament. It was clear against Ireland that England won't miss a trick wherever the captain plays.
13. Manu Tuilagi
Has returned to his destructive best, a sight many English coaches hoped for, but rarely saw. With Ben Te'o jettisoned, Tuilagi has to stay fit. A trump card.
14. Anthony Watson
Jack Nowell would be in strong contention to start on the right wing - but has been battling injury and illness and can't be risked. Watson is back from his long-standing Achilles problem and looking sharp. Can interchange with Daly in attack and defence.
15. Elliot Daly
Daly at full-back has not been wholly convincing - which is why I would have had the safety blanket of Mike Brown in the squad - but he must play somewhere in the back three. His footballing quality will spark England on the counter-attack, which is why Jones puts him at 15 rather than on the wing.