Peruse the long list of world footballing stars in 2013 and you'll notice a lack of world-class defenders.
It applies to centre-backs just as much as it does full-backs, and players like Philipp Lahm, who are well-rounded, elite players, are far too sparse for comfort.
It begs the question: where have all the world-class defenders gone?
The answer to that question is a multi-layered explanation, and it starts with the fact that this ever-changing sport is evolving so fast it's almost impossible for players to keep up.
Back in the 1990s, when football boasted names such as Paolo Maldini, Jaap Stam, Paul McGrath and Fabio Cannavaro at their peaks, defending was an extremely different proposition to what we value today.
A centre-back would know he is always going to come up against a dedicated centre-forward, most likely in the Duncan Ferguson mould, and they'd have a one vs. one tussle that could decide the outcome of the game.
The ability to pass out from the back was a luxury that managers would take if they could but certainly not prioritise, and "old-school tackles" were still very much allowed.
Bruising, blood-covered centre-backs were lauded as warriors, saviours; if you weren't getting stuck in then you weren't a "proper centre-half."
Fast-forward to today and you've got very little of that left, and you get the impression football is moving away from a concept that values and appreciates "quality" defending.
They're judged on different metrics, alien to those McGrath would have dealt with, and the way the game has changed over the last 10 years has contributed heavily toward the fall of the defender.
Defending is being devalued, with the entertainment factor of goals and silky skills in football a far larger crowd-pleaser worldwide.
There's also the safety-conscious rule changes that hamstring defenders badly when looking to make a challenge, as you can no longer lunge, leave the ground, tackle from behind or lead with your upper body.
Crunching tackles from Julian Dicks would receive raucous applause when he was around, but Wes Brown's latest attempt at a firm (and fair!) tackle bagged him a straight red card against Stoke City.
The physical aspect of the game is utterly diminishing when it comes to the classical battles between defender and forward, and players are being forced to perfect—and we mean perfect—the art of the tackle just to stay card-free. There's no room for error.
But perhaps the biggest "game-changer" for defenders is the tactical progressions made over the last 10 years, with both their own and forwards' roles changing dramatically to catch many out.
The Ferguson vs. Steve Bruce tussle is gone, shelved for the time being; replacing it is the intricate movement of Sergio Aguero as he tries to exploit a high defensive line, lead by Mats Hummels, by dipping in and out of the midfield.
That escalated quickly.
Ball-playing centre-backs are all the rage as we have moved into a possession-orientated game. Pep Guardiola's Barcelona set a standard of passing, and ever since many fans have yearned for their team to try to replicate that.
His side also included flying full-backs, and that position has been changed—for better or for worse—by the performances of Dani Alves during that memorable UEFA Champions League-winning season for La Blaugrana.
In short, centre-backs need to be midfielders in disguise and full-backs should essentially be deep-lying wingers.
That football is in transitional period, where hard-case defenders convert into more graceful, aesthetically pleasing outlets, is a big reason as to why there is a genuine lack of world-class players in that position.
Sergio Ramos, who played a fair chunk of his career at right-back for Real Madrid and Spain, has been moved (permanently) back to his original role of centre-back and represents the perfect collaboration: good size, ball-playing prowess, strong in challenges and possessive of the requisite recovery pace.
Thiago Silva, too, combines all of those qualities, while Dante comes rather close and Vincent Kompany fits the bill when he's not sidelined through injury.
Lahm is the best full-back in the game, and arguably the best defender on the whole. His colleague David Alaba has emerged as the best left-back, and that's largely due to the fact that he can both attack and defend with equal skill.
Doubts swirl over Jordi Alba, and Barca's back-up, Adriano, looks a more "complete" player right now, while Ashley Cole has lost his offensive edge.
The rest? caught in the middle of a wild transition, where the fundamentals of a "great" defender have shifted in seismic fashion over the past five years.
The bar has been raised extremely high, and any defender without all of the above qualities will find it tough to be labeled universally "world-class."
If you were an up-and-coming 21-year-old prospect nine years ago, it's likely these changes have rendered you a rather average player.
The next generation of centre-backs—we're talking Marquinhos, Eder Alvarez Balanta and Raphael Varane—must come to the fore, possessing all the requisite "modern skills" to become world-class defenders. Marquinhos and Varane are well on their way.
Likewise, players such as Luke Shaw who can defend first and attack with equal excellence, will prove to be hot commodities.
Until then we must wait, and as the next crop of footballers are schooled in modern methods, perhaps hope the game doesn't move so far it leaves them behind too.