Who are the best full backs in world football right now?
It's a tough question to answer because never before has the game demanded so much from players in the role.
A decade ago, nobody really minded if a right or left back could guarantee you a wicked delivery and a hatful of assists each season.
Yet nowadays, we judge the performance of these players that are still technically classed as defenders based upon their attacking exploits, too.
Players like Trent Alexander-Arnold, Joao Cancelo and Andy Robertson have been pioneers in the Premier League for the modern-day full back.
But who's the best in the world right now?
We've ranked 45 of the best full backs from 'great asset' to 'best in the world' and you can view our findings below.
'Great asset'
Luke Shaw, Raphael Guerreiro, Renan Lodi, Alex Sandro, Aaron Creswell, Benjamin Pavard, Marcos Alonso, Denzel Dumfries, Kostas Tsimikas, Matty Cash, Lucas Digne, Takehiro Tomiyasu, Jesus Navas, Ricardo Rodriguez, Ben Davies, Nelson Semedo, Filipe Luis, Marcelo, Alex Telles, Sergio Reguilon, Danilo, Alessandro Florenzi
A mixture of different types of players make up the 'great asset' category from legends that are slowly on their way out to solid Premier League stars.
Marcelo, Navas, Sandro and Luis all fall into the former having enjoyed exceptional careers. None more so than Marcelo, who has lifted an incredible five Champions League titles.
Cash and Digne represent two useful tools Steven Gerrard has at his disposal. The pair have proven very effective going forward for Aston Villa and are classed as fan favourites in the west midlands.
Meanwhile, West Ham fans will say much of the same when it comes to Creswell, who could make this section just for his free kick taking ability alone.
Shaw, Telles, Tsimikas, Davies, Semedo, Alonso, Tomiyasu and Reguilon make up the remaining Premier League players who could be deemed an asset to their club.
None of the eight would be considered leading full backs but solid options at this stage of their careers.
'Elite player'
Marc Cucurella, Kieran Trippier, Oleksandr Zinchenko, Kieran Tierney, Sergino Dest, Nicolas Tagliafico, Ricardo Perreira, Marcos Acuna
Plenty more quality fills this category, headlined by none other than Chelsea's new £60 million signing Cucurella.
Zinchenko also moved between Premier League clubs this last summer and has been excelling for Arsenal so far this campaign.
The Ukranian could be deployed as a left back or in the centre of midfield, although given Mikel Arteta also has Tierney to call upon in the defensive role it's likely Zinchenko might find himself further forward.
Trippier will provide plenty of competition for places in the England team at the upcoming World Cup, meanwhile fellow Premier League star Perreira will likely be forced to play second fiddle to Cancelo in the Portuguese set up.
Tagliafico and Acuna will also battle it out for a starting spot in the Argentina squad.
'World class'
Andy Robertson, Kyle Walker, Lucas Hernandez, Theo Hernandez, Ferland Mendy, Ben Chilwell, Jordi Alba, Dani Carvajal
Now we really are approaching the best. Liverpool's Robertson and Man City's Walker can certainly count themselves unlucky to have missed out on a 'top five' spot given they were both well within that realm for a number of years.
We also have three French stars within the 'world class' section which bodes brilliantly for Les Bleus when it comes to this year's upcoming World Cup.
Mendy and Hernandez (Theo) will battle it out for the starting left back spot. Whilst Hernandez (Lucas) can play left back but is often also deployed as a centre back for Bayern.
Chilwell and Alba are both exceptionally good in an attacking and a defensive sense and are well worthy of their lofty ranking.
Carvajal was vital in Real Madrid's Champions League triumph, emphatically proving his worth in a brilliant performance in the semi-final vs Man City.
'Top 5 in the world'
Reece James, Achraf Hakimi, Alphonso Davies, Trent Alexander-Arnold
Up until this season, we probably would have given Alexander-Arnold the tag of 'world's best', however, the Liverpool star has been too out of form so far this campaign to warrant the accolade.
Fellow Englishman James is also good enough to be placed within the top five full backs in the world.
And the final two placings go to Hakimi and Davies. Two of the fastest players you're likely to see ever, these two have been revelations since bursting onto the scenes and are treasured by PSG and Bayern.
View the full Tiermaker below:
'Best in the world'
Joao Cancelo
But there can only be one player that tops this ultra-competitive ranking and based on recent performances, Cancelo just about edges it.
The versatile Man City star can play as either a right back or left back and is just as effective on both sides of the pitch.
From an attacking standpoint, he's both brilliant creatively and a goal threat. However, it's the consistency in his defending which gives him the edge here.