A good fullback can make a huge difference to a club's performances on the pitch—both attacking-wise and defensively.
Often these players can be criticised for neglecting one of these areas over the other, but in the modern game they have to be adept at both to be considered the best.
In no particular order, here are 20 of the best fullbacks in world football today
Unless he's pitted against Gareth Bale, Maicon consistently has been one of the best fullbacks of the modern era for Serie A side Inter Milan.
The Brazilian International does as much damage in attack as he does when it comes to defending his own goal.
His tireless work ethic allows his fellow players to find more space to open up the opposition.
Barcelona fullback Dani Alves is probably the best in the world right now.
Alves seems to drift between defensive and attack-minded duties with ease and has been a key performer in the Barcelona side that has won so many trophies over the past half decade.
Truly world class.
Bayern Munich and Germany fullback Philip Lahm certainly runs Dani Alves close in the best-in-the-world stakes.
Lahm, whilst approaching the twilight of his career, is undoubtedly still a high quality player.
Lahm has been the mainstay of the German national team throughout his career.
Ashley Cole has been England's first-choice left back without question for the past 10 years.
The Chelsea defender has great pace which allows him to recover from his rare mistakes.
Manchester United signed Patrice Evra for £5.5 million and what a bargain he has proved to be.
The French defender has been the subject of a race row of late involving Liverpool forward Luis Suarez.
Real Madrid wouldn't be the force they are without strength in all positions. Sergio Ramos certainly typifies that.
Ramos is a World Cup and European Championship winner with Spain.
Gianluca Zambrotta might be 35 years of age, but still plays at a top level for AC Milan and Italy.
If you are unsure of his pedigree, his previous clubs include Juventus and Barcelona.
If Gianluca Zambrotta is old, then Javier Zanetti must be ancient.
The 38-year-old tends to play in midfield these days, so this is more of an honorary mention for the Argentine legend.
Zanetti's nickname is "the tractor," which gives you an idea of the work rate he achieved for Inter Milan in the fullback position.
Borussia Dortmund left back Marcel Schmelzer is a German International who adds a lot to the impressive Dortmund defense that already boasts Neven Subotic and Mats Hummels.
Schmelzer has more than 80 league appearances for the club to date.
Liverpool struggled for years to replace John Arne Riise in the left back position when they sold him to AS Roma.
Fabio Aurelio, Emiliano Insua and Andrea Dossena all tried and failed to hold down the position that eventually was made secure by Jose Enrique.
Enrique is yet to earn a full Spain call-up, but surely it is only a matter of time.
Real Madrid fullback Fabio Coentrao is only 23 years of age, but he already has made a huge impact in his short footballing career.
Coentrao is a full Portuguese International.
Real Madrid are well-stocked for fullbacks. They have the Brazilian International Marcelo to go with Coentrao and Ramos.
Marcelo is a left back who has nine full Brazil caps.
Glen Johnson became an England regular at right back once he had started performing consistently well for Liverpool FC.
Occasionally criticized for neglecting his defensive duties, Johnson makes up for it with an attacking threat.
Arsenal defender Bacary Sagna has been one of Arsene Wenger's best signings in his many years at the club.
The French right back rarely makes any mistakes and is regarded as the club's Mr Reliable.
Manchester City full back Bacary Sagna has consistently been Roberto Mancini's first-choice right back when fit.
Fabio Capello's recent departure from the England national team has now given Richards the opportunity to show his country he is up to the task.
Eric Abidal is 32 years of age but still covets a full back position at one of the best clubs in the world.
The Barcelona and France International recovered from a tumor in his liver to continue performing at an extremely high level.
FC Porto right back Danilo may be young at 20 years of age, but his quality isn't in question.
Danilo played 80 league matches for Santos before signing for the Portuguese club and is already a Brazilian International.
He can also play in midfield and is surely only going to get better.
Tottenham Hotspur full back Kyle Walker has come on leaps and bounds over the past season and now rivals Micah Richards and Glen Johnson for the England right-back role.
Walker has superb speed.
Similar to Javier Zanetti, Roberto Carlos has to get an honorary mention.
Roberto Carlos was perhaps one of the best fullbacks that ever played the game, and he certainly made the Brazil left wing-back spot his own.
Carlos is still playing the game at 38 years of age for Russian club Anzhi Makhachkala—albeit in a defensive midfield role these days.
One of the true greats.
There seems to be plenty of Brazilians making up this list, which is testament to their playing style.
Left back Felipe Luis is Atletico Madrid's star Brazilian who should have more caps than he does.
A bad leg break cost him some International exposure, but now he is fit and ready to reclaim the spot once offered to him.
A great overlapping player.
So there you go, 20 of the best fullbacks in the modern game.
I don't think there will ever be a fullback pairing that will achieve what the likes of Roberto Carlos and Cafu did together for Brazil.
When I think of great fullbacks, that is who springs to mind immediately.
Players can come and go over time, but the true greats will always be remembered.
Thanks for reading and be sure to check out Serie A vs. La Liga and my views on which division I think is better. The answer might surprise you.
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