It's good -- and fun -- to focus on positive things -- "Who are the best players?" or "Who are the best teams?" But it can also be fun to look at the other end of the spectrum, dissecting some of the worst teams in recent history.

With that being said, how do we determine what the worst seasons are? Do wins and losses say it all? What about win percentage or playoff success?

You can do that -- sure -- but going back to 2000 our nERD metric does the most effective job in showing who are the worst (and best) teams are in recent years. How? Well, nERD is a team ranking, on a scale of 0 to 100, with 50 as league average. The ranking is predictive of a team's ultimate winning percentage for the 82-game regular season.

So while nERD does not account for postseason play, it does tell us which teams were the best over the long-haul of a large sample size, regardless of record. In the same way, it tells us which ones were the worst, which is what we are concerned with here.

Utilizing that metric, here are the 10 worst teams of the 21st century to date, starting with the highest and finishing with the lowest nERD we have ever seen here at numberFire.