Some sports rely on rankings, and others use them for conversation. College basketball, for instance, really doesn't need polls of any sort, but college football relies on them (at least, until the impending playoff goes into effect). For some sports, point totals are everything -- NASCAR and soccer, for instance. But in no sport are rankings more relevant than in tennis. Rankings often determine not only seeding, but qualification. One break here, one ratings boost there, and you can move from qualifying tournaments to the bigger draws.

It is a bit problematic, then, that the systems used by the ATP men's tour and the WTA women's tour are a bit arbitrary and, in some cases, in no way indicative of actual skill. The luck of your tournament draw, especially in larger tournaments, determines almost as much of your ranking as your ability does.

Here's the general structure of the ATP point system, for instance.

Type of Tournament W F SF QF R16 R32 R64 R128 Q Grand Slams 2000 1200 720 360 180 90 45 10 25 Barclays ATP World Tour Finals 1500* ATP World Tour Masters 1000 1000 600 360 180 90 45 10(25) (10) 25*** ATP 500 500 300 180 90 45 (20) 20*** ATP 250 250 150 90 45 20 (5) 12*** Challenger 125,000 125 75 45 25 10 5 Challenger 125,000 110 65 40 20 9 5 Challenger 100,000 100 60 35 18 8 5 Challenger 75,000 90 55 33 17 8 5 Challenger 50,000 80 48 29 15 7 3 Challenger 35,000 80 48 29 15 6 3 Futures** 15,000 35 20 10 4 1 Futures** 15,000 27 15 8 3 1 Futures** 10,000 18 10 6 2 1 *Barclays ATP World Tour finals 1500 for undefeated Champion (200 for each round robin match win, plus 400 for a semi-final win, plus 500 for the final win). ** ATP Doubles Rankings points will be awarded in Futures tournaments beginning with the semi-final round. *** For ATP 1000: 12 points only if the main draw is larger than 56. For ATP 500: 10 points only if the main draw is larger than 32. For ATP 250: 5 points only if the main draw is larger than 32.

Now, generally speaking, the best players are going to rank the highest in a system based on points. You don't need advanced analytics, in other words, to determine that Novak Djokovic is the best, most consistent tennis player in the men's game. But away from the top tier, your ranking is determined as much by which tournaments you qualified for or entered, and how many easy first-round matches you perhaps drew or byes you received. In this way, tennis rankings can be incredibly unfair.

So we've created a better way. Over the last few months, I've been working with Colin Davy to create a measure we're calling Advanced Baseline. Think of it as a Ken Pomeroy rankings system for tennis, one that is at once both evaluative and predictive, one that rewards actual performance.

(To be clear, by the way: Colin did the work here. I just helped with quality control checks, outliers, and, now, promotion.)

Here's Colin on some of the nitty gritty details.

What makes this rankings system fundamentally different from the ATP/WTA formula is that they’re volume-independent: unlike ATP/WTA rankings, they’re not a simple tally of wins with pre-determined point values according to tournament and round progression. The basic procedure for determining the base ranking for each player is as follows: For each match in the evaluation period, the model estimates the probability of the winner being a better player than the loser based on the score of the match (so a 6-2, 6-1 victory will count more in the winner’s favor than a 7-6, 3-6, 7-5 victory).

The score-to-probability conversion is based on a best-fit curve that’s constructed outside of the rankings algorithm itself. From there, the head-to-head probabilities are collided against each other to reconcile the messy and often-times contradictory results from actual match play (i.e. how good is Sloane Stephens really, given that she beat Serena Williams at the Australian Open but lost to Ursula Radwanska 2 months later at Indian Wells?), with greater weight placed on more recent results. The output of this process is a steady-state rank order of players that ends up being powerfully predictive .

. The surface adjustments to each player’s base ranking are calculated using a completely separate module that takes the base rankings as its input. The base rankings are used to predict head-to-head win probabilities for each future matchup. Over time, the module compares how often each player is expected to win (from the predicted win probabilities) to how often they actually win for each surface. The difference between expected win rate and actual win rate is the feedback signal that drives the surface adjustments: when Rafael Nadal starts winning on clay courts more often than the model says he will (or when Andy Roddick loses more often than he should), their rankings will be adjusted accordingly for that surface. So what’s the benefit of using something this complicated to rank players over the existing ATP/WTA system? For one, it does a much better job of rewarding players that beat top-tier competition: if you beat a top 25 player, you get the same amount of credit no matter what round of the tournament in which it happened. Second, it does a good job of filtering out players that get an oversized boost to their rankings from simply playing a high volume of tournaments and/or players that win tournaments with weak field strengths (i.e. Juan Monaco winning Hamburg 2012 when most top-tier players were resting for the Olympics). And third, taking scoring margin into account provides a lot more insight: not only does it help filter out “lucky” wins, but it also helps differentiate between the lower-level players who can’t get accepted into anything besides Futures/Challenger Tour tournaments.

Quite simply, Advanced Baseline ranks players by their performance in matches, not tournaments.

Below are the Advanced Baseline men's rankings for March 11.

Some notes:

Among the ATP's Top 100 (also included below), those most underrated by the ATP (and highly rated by Advanced Baseline) are, in general, older players who don't play as many tournaments due to either choice or injury: David Nalbandian (ATP No. 93, AB No. 17), Lleyton Hewitt (ATP No. 98, AB No. 33), James Blake (ATP No. 99, AB No. 60), Tommy Robredo (ATP No. 69, AB No. 47), Mardy Fish (ATP No. 32, AB No. 18). But there are some other players who have perhaps experienced some bad luck in the rankings: Jesse Levine, Carlos Berlocq, Santiago Giraldo, Yen-Hsun Lu, Paul-Henri Mathieu, Michael Llodra, Jarkko Nieminen and Ernests Gulbis are all in the AB Top 50 but outside of the Top 50 in the official rankings.

On the flipside, quite a few players have reached the ATP Top 100 by either playing in a lot of tournaments or getting good draws, but not necessarily playing at a Top 100 level: Pablo Andujar, Tatsuma Ito, Martin Alund, Joao Sousa, Go Soeda, Paolo Lorenzi, et cetera.

I don't think David Ferrer is going to be above Rafael Nadal for too long.

At 34, Tommy Haas might still be one of the 10 best men's tennis players in the world. That's staggering. But he needs to bring it in a slam for once -- he's lost in the first round of three straight. (Best-of-5 might be his undoing at this point.)

Your Top 20 Americans (not including Andy Roddick, who hasn't quite cycled out yet) :

1. Mardy Fish (AB No. 18)

2. Sam Querrey (No. 20)

3. John Isner (No. 29)

4. Brian Baker (No. 51)

5. James Blake (No. 60)

6. Ryan Harrison (No. 80)

7. Michael Russell (No. 83)

8. Steve Johnson (No. 98)

9. Jack Sock (No. 114)

10. Tim Smyczek (No. 119)

11. Ryan Sweeting (No. 122)

12. Bradley Klahn (No. 127)

13. Rhyne Williams (No. 130)

14. Wayne Odesnik (No. 131)

15. Donald Young (No. 141)

16. Rajeev Ram (No. 154)

17. Bobby Reynolds (No. 157)

18. Denis Kudla (No. 169)

19. Alex Kuznetsov (No. 190)

20. Daniel Kosakowski (No. 240)

I honestly thought Ryan Harrison might benefit from the AB rankings. His slam draws have been so incredibly unlucky through the years (it seems he's always playing a Top 10 player by the second round at the latest) that it seems like luck has prevented him from racking up a higher ATP point total. Alas, these rankings show he still has a long way to go.