In any sports, stats aren't everything, and rarely do they paint a complete picture.
As you've probably discovered reading through this slideshow, a good all-around defender ought to average a good number of tackles per game, a good number of interceptions per game and a good number of clearances per game.
It would also be helpful to be a good passer of the ball as well.
But as we saw by looking at Carles Puyol and Gerard Pique (see: Dani Alves' slide), some of the world's best defenders don't have especially impressive stats in any of the usual standout categories for defenders, and yet are still regarded as the best of the best.
Stats can never give you a 100 percent indicator of who is the best and who isn't, but they can help shape the discussion, create trends and provide indicators for determining who is good and who isn't, or help you compare two players with each other.
Secondly, you may have noticed that although I ordered this list from the player with the lowest number of tackles per game to the player with the highest number of tackles per game, I didn't rank the players.
That's because over the span of just a couple of games, many of the players on this list will likely move up or down a few spots, which would render this entire list invalid in just a couple of weeks.
That isn't my goal. My goal is to have this list still be relevant and applicable one or two months down the line, or even at the end of the season.
I expect a significant amount of movement moving between the rankings of first through 32nd between now and Euro 2012—but I don't expect very many players at all to fall out of these top 32 spots.
Finally, it is important to note that had I simply listed the usual names here—Thiago Silva, Alessandro Nesta, Carles Puyol, Gerard Pique, John Terry, etc.—only a few readers would doubt the quality of the article, or the legitimacy of my claims.
While this is not necessarily a call for readers to be more skeptical of what they read, it is a call on writers and readers alike to be open-minded with the topics they approach, and try to move away from talking about the same batch of players for every type of list that comes along.
Indeed, football is an ever-changing sport, and with it, the best players are constantly changing as well. Without a doubt, the best of the best are able to withstand the test of time and stay at the top, but sometimes we do the job for the players and allow their reputation rather than their play to keep them on our "best of" lists.
So stay inquisitive, and avoid stagnation. Because we all know what happens in football when you get stagnant as a club, as a national team or as a player on the pitch.
You get tackled hard by the opposition.