Eddie Jones believes test rugby has evolved into a hybrid of the NFL and football in the past 12 months, a trend he believes will place a great onus on pace, power and tactical kicking at the World Cup.
Such a shift, comprising longer passages of "unstructured" play, has contributed to selection reassessments in certain positions over the latter part of this four-year cycle.
Prioritising the speed of Elliot Daly and Anthony Watson at fullback over the experience of Mike Brown has been one result of the England head coach's logic.
"Brown is a great fullback." said Jones. "He's a great defensive fullback, but we feel, the way we want to play, we need a fullback who can attack and with pace. Fortunately for us, Daly and Watson are our best options.
"The game keeps changing. I see this game now where it is basically a mixture of NFL and soccer. You have got the first three phases that are basically all power and precision. Then you have the kick-return game which then becomes football.
"That sort of analogy for us became clear in the last 12 months and that's why we've gone to having a more X-factor type fullback who can be more commanding in that more unstructured rugby."
Daly, who started the 13-6 defeat against Wales on Sunday and was bombarded by high balls from Dan Biggar in the early exchanges, estimated the international game is now "65 per cent unstructured to 35 per cent structured". While there are generally fewer opportunities to launch first-phase moves, a set-piece platform remains so valuable that carefully-choreographed shapes, akin to offensive plays in NFL, are drilled meticulously.
Jones also highlighted centre Henry Slade, "a 13 who can kick, run and pass", as England aim to manipulate back-field defences and find space by putting boot to ball. Grubbers, dinks and chips were prominent weapons as they amassed 24 tries in this year's Six Nations.
The composition of England's back row is another interesting consideration. The candidates are undoubtedly working hard. Jones revealed that Billy Vunipola had "run 300 metres further than he ever has in a game" during the 33-19 win over Wales at Twickenham nine days ago.
Confirming that Tom Curry and Courtney Lawes would be seen as potential blindsides in Japan but that Maro Itoje would remain at lock, Jones suggested the back row would be altered according to England's opponents. Teaming up Curry and Sam Underhill, for example, might be problematic against a team with more than two specialist lineout jumpers.
"We played Wales the last four years and averaged five lineouts a game, so the lineout is not a significant factor against them.
"But we played New Zealand in November and they schooled us in the second half in the lineout. They had [Scott] Barrett, [Kieran] Read, [Sam] Whitelock, [Brodie] Retallick and we couldn't win the ball.
"They had four jumpers and I think we lost five lineouts and it probably cost us the game. Against New Zealand, we have to have a jumping back rower. They are a huge kicking team."
There is still time for England to add variety. In naming his 31-man squad around a month before World Rugby's deadline of September 8, Jones has aimed to "minimise the noise", adding external distractions may have been possible because "the media is more powerful [in England] than anywhere else in the world".
Having said that, first-five George Ford hinted humid weather expected in Japan and simulated at England's training camp in Italy could enhance the value of a strong kick-chase.
"The thing we noticed most in Treviso was how the humidity affected the sweatiness and greasiness of the ball," Ford said. "It was like playing in wet weather sometimes, and sometimes in wet weather, you are better off without the ball. You've got to understand when it is going to be like that and how difficult it is going to be to keep the ball. That might bring the kicking game into play more and having a really strong defence."