It is the debate which seemed to have been settled a few years ago – is the modern full-back really a defender any more, or is he closer to a winger?
Pep Guardiola's Barcelona really changed the game, with Dani Alves often operating so high and wide on the pitch that he was part of the attacking unit. Manchester City have followed that trend.
Liverpool have earned plaudits for years under Jurgen Klopp for how their defenders push up the pitch, not least Trent Alexander-Arnold. The 21-year-old has emerged as a brilliant provider of assists and can cross the ball like David Beckham in his prime.
Gone, seemingly, were the days of wide defenders simply being cloggers. The conversation seemed to be over. All hail the flying full-back.
And yet, in another part of the north west, a new point is being made in the discussion.
Aaron Wan-Bissaka, like Alexander-Arnold, is part of a glut of talented right-backs that have emerged in England in recent years.
He broke through at Crystal Palace under Roy Hodgson, looking solid beyond his years, and earned a £50million move to Manchester United in the summer.
Unlike Alexander-Arnold, though, his game is all about defending. Over the weekend, Rio Ferdinand said: 'If you moulded them two players together, Aaron Wan-Bissaka and Trent Alexander-Arnold, you've got the best player.
'Aaron Wan-Bissaka one-versus-one, I've seen [Raheem] Sterling play against him and Sterling rinses everybody, he finds it hard against Wan-Bissaka.
'One-versus-one he will match you physically, he will run with you, he will slide on the floor if you're getting away from him a little bit more and he has to go into overdrive.
'He can cover people, unbelievable. He could play right side of a back three at Man United if they wanted to, I think he'd be brilliant there.'
He also acknowledged Wan-Bissaka's flaws compared to Alexander-Arnold: 'On the ball nowhere near as good as Trent, but Trent defensively one-on-one isn't anywhere near as good as Wan-Bissaka, so if you had both of them you've got the ultimate machine.
'It depends on the game. If I knew I was going to have to defend a lot and I need someone to lock down the winger I'm bringing Wan-Bissaka on.'
Ferdinand hit the nail on the head when it comes to the pair. You will likely not see a pair of players operating at the elite level in the same position who have as disparate styles of play.
The stats back his point up too. Alexander-Arnold has 12 assists to his name in the Premier League this season, while Wan-Bissaka has two. The United man has no goals, compared to Alexander-Arnold's two.
Go deeper into the stats going forward and the difference becomes even clearer. Liverpool have seen 75 chances provided by Alexander-Arnold – the most in the Premier League for a defender – while Wan-Bissaka has provided just 20 for his team-mates.
Admittedly, only 40 of Alexander-Arnold's are from open play – he is also a set-piece specialist – but that's still a huge gap.
Wan-Bissaka has attempted less than half the number of crosses Alexander-Arnold has put in – at 75 compared to 195 – which says a lot about the Liverpool man's positioning.
And while Alexander-Arnold has managed 48 touches in the opposition box, putting him 10th in the division for defenders, Wan-Bissaka does not crack the top 10.
On the other hand, Wan-Bissaka hugely outperforms Alexander-Arnold in defensive metrics.
The 22-year-old has managed 99 tackles in the Premier League this season, putting him second for defenders behind just Ricardo Pereira. Meanwhile, Alexander-Arnold has attempted just 45 tackles.
Guardiola once famously said he did not coach tackles, and it is fair to say that the sliding challenge has gone out of the game to a degree.
Positioning and organisation is just as important.
But what is a small issue is that Alexander-Arnold has consistently been dribbled past more by opponents than Wan-Bissaka.
He has suffered that fate 40 times this season, compared to Wan-Bissaka's 19.
It allows Wan-Bissaka to completely mark the likes of Raheem Sterling out of games, while Alexander-Arnold sometimes gets dropped in favour of more solid options for big matches.
Wan-Bissaka has also won more duels, at 175 to Alexander-Arnold's 60.
What is clear is that Ferdinand was right. As it is, these are two brilliant full-backs with one sizeable flaw in their game. If you were to mesh them together, you'd have an all-time great player in the position.
The real test will be seeing who England go for in the future. It will be a symbolic choice, a decision between solidity and creativity.
At the least, the debate is now back on. What is a modern full-back? When it comes to Alexander-Arnold and Wan-Bissaka, two different answers have emerged.
Pasaeiryz
473
Trent is better offensively,but Aaron is defensively but i can see the development in Aaron in attack.if we look at last 10 games of this two chances created by Aaron is more than the Trent's and imo Aaron will be the best rb in the following years with the competition vs Trent.
Lebaenprz
433
first of for most a RB is defender meaning his number one priority is to defend. let's put it this way, If Arnold doesn't play for city or Liverpool then he will struggle massively. if wan bissaka played for Liverpool or city, he would not be as good as Arnold but would still do better than he is at united. to conclude wan bissaka is the better of the 2. And Arnold will be exposed plying for England. Just watch!
Hesbceory
317
in modern football you don't need backman at the right back but a player we can create goals, the statistics prove that. the likes of Cafu R.Carlos, Lizarazu, etc.
Jarein
244
I'd rather have a defender than can actually defend and not attack ,than one that can't defend at all but is superb going forward. I'd buy wingers and creative midfilders for the forwards plays
Kendrick_jnr
175
I'd say in Euros England should take both players, when facing a lesser opponent that England will be the more attacking team and face less treat defensively they take Trent, but when facing a big team like France, Spain etc, they should use AWB because of his defensive prowess
jaazibshah
161
Wan -Bissaka is more a spider man 🕸! It may sound weird but I guess he’s got that name due to the fact that he sticks on his opponents and makes sure they don’t get a chance to even attack ! And that is why he has become Raheem Sterling’s Biggest and Worst Nightmare ! TAA is in a way a bit better ! He has one of the best crossing ability 🎯as a defender and Much as well can defend ! Playing for Liverpool is what sort of makes him better than AWB !
Clerk_FB
160
The Story of Wam Bisaka and Trent Alexander is like Marcelo and Mendy... Marcelo and Trent Have the same similarities as they Are Attackingly Machines
Bisaka and Mandy have the same qualities as they Are Defensively Monsters [Comeon][Comeon]
sims123
110
Don't know why people hide under that AWB can't attack,And it's a big lie coz he has improved and he's now going forward more now. If I'll choose, I'll choose AWB coz he'll always deliver no matter what,he's on. if he were at Arnold position against atleti,they'll be difference. AWB is the best 1v1 defender in the world.🐐🕸