This article has been updated! You can now see the top 15 leagues in CONCACAF here!

Which soccer league is the best? It's a question that fans often ask themselves, but the soccer world is short on definitive answers. Commissioner Don Garber wants MLS to be among the top leagues in the world by 2022. But how will we know his league has arrived?

Alexi Lalas also wondered recently if leagues can be judged objectively. That "subjective" comment is a challenge.

If you say a league is "objectively better" then you should say specifically what makes it so (besides $.) But I say better is subjective. — Alexi Lalas (@AlexiLalas) March 1, 2015

If we wanted something objective, a reasonable way to answer this question would be to look at the tournaments that match different teams from different leagues. UEFA has developed a tool that does this. They publish UEFA coefficients for countries based on the win-draw-loss results of the UEFA Champions League and Europa tournaments. They also add bonus points for advancing through the stages of the tournament. It's not terribly scientific, but the ranking basically separates the strong from the weak.

CONCACAF of course has its own Champions League. There's also the Caribbean Cup, and in addition to that countries that are large enough to have multiple leagues have club tournaments within the country. They are not necessarily administered by CONCACAF, but they provide insight nonetheless. Copa MX in Mexico and the U.S. Open Cup are examples in the CONCACAF region.

The following ranking is an attempt to build a more accurate depiction of league strength across CONCACAF. It uses the biggest tournaments in CONCACAF (CCL, Copa MX and US Open Cup) as well as league standings to create a index of league quality. This index will take something into account that the UEFA coefficients do not, and that is the depth of each league. UEFA coefficients are based only on the results of team's in the tournament. But to rank a league completely, there has to be a method of evaluating the quality of the teams below the qualifiers.

A detailed review of the methodology is here, but this is a brief description of the criteria used:

1. Tournament GDI (goal differential index) is an estimate of the goal differential that would occur if a top team in the league played a top team in Liga MX at a neutral site.

2. The depth of the league is rated by looking at the goal differential of the top teams over the last two seasons. Then a formula calculates the quality of the rest of the league based on those results to create a depth adjustment to the GDI..

3. The Tournament GDI and depth adjustment are added together to make the Total GDI. The Total GDI in theory measures the goal differential that would be expected if the average team in a league played an average team in Liga MX on a neutral site.

Here are the best 10 ranked by Total GDI:

10. USA & Canada - USL (-2.1 Tournament GDI, -0.4 depth adjustment, Total GDI -2.5)

We start with what many will consider a surprise league in the top 10, but USL scores just a little better than 11th place Nicaragua. Over the last four years of USOC history, USL teams average a -0.5 goal differential when hosting a MLS team, and MLS has a +1.3 goal differential when hosting a USL team. Compare that with Nicaragua against MLS in the CONCACAF Champions League. Nicaragua averages -1.0 at home against MLS and -1.3 on the road. It's pretty close but when you factor in that Nicaragua's best team is representing the league in the CCL and USL has a broader set of teams playing in the USOC, the separation between the two is more convincing. USL's growth and tie to Major League Soccer bodes well for the future of the league and the opportunity to move up this list over the next few years.

9. El Salvador - Primera Division (-2.4 Tournament GDI, 0.0 depth adjustment, Total GDI -2.4)

Santa Ana's FAS and Isidro Metapan represented El Salvador in this past year's CCL. Both teams struggled as combined they only earned one point in eight matches and had a -15 goal differential. Isidro Metapan did make a quarterfinal run in the CCL very recently in 2012. The league however, is one of the deepest in CONCACAF and that pushes them past 10th place USL.

8. Guatemala - Liga Nacional (-1.6 Tournament GDI, -0.5 depth adjustment, Total GDI -2.1)

Municipal and Comunicaciones dominate the top league in Guatemala with 58 combined championships. The result is that Liga Nacional has the least amount of depth in the top 10. Comunicaciones performed well in their Champions League performance this past campaign, earning seven points in four matches, but were unable to move to the quarterfinals.

7. USA & Canada - NASL (-1.6 Tournament GDI, -0.2 depth adjustment, Total GDI -1.8)

Formed in 2009 the North American Soccer League has performed well in the U.S. Open Cup. In that tournament they have a +0.1 goal differential at home against MLS and a -1.2 average on the road. Guatemala is close but still comes up short compared to NASL. They have a +0.5 average goal differential at home against MLS but -2.0 average on the road. Guatemala's lack of league depth is also a factor that ultimately puts NASL a notch above.

6. Honduras - Liga Nacional (-1.7 Tournament GDI, 0.0 depth adjustment, Total GDI -1.7)

Honduras' historic Olimpia went through to this year's CCL quarterfinal and the league is one of the most competitive leagues in the region. Over the course of their last three seasons there have been three different champions and seven different clubs in the semifinals.

5. Panama - Liga Panamena de Futbol (-1.7 Tournament GDI, +0.1 depth adjustment, -1.6 Total GDI)

Panama's top league, LPF, barely edges out NASL and Honduras' Liga Nacional due to their region best league depth. Tauro and Chorillo performed below expectations in this year's CCL, but overall, Panama has performed well in the tournament and has good mix of title contenders each season.

4. Costa Rica - Primera Division (-1.1 Tournament GDI, -0.4 depth adjustment, -1.5 Total GDI)

Ajajuelense, Herediano, and Saprissa are consistent names in the Champions League year in and year out, and all three qualified for the quarterfinals during the current tournament. Herediano and Alajuelense reached the semifinals. But those latest games are not factored into this ranking. Only the big three teams have won their league title since 2010. In fact, one of those three teams has won every league titles but five dating back to 1947. Parity is not this league's strength, but they still remain a force in the Confederation based on the strength of the top three clubs.

3. USA & Canada - Major League Soccer (-0.9 Tournament GDI, -0.1 depth adjustment, Total GDI -1.0)

Garber has his league in the top of this region. Check. MLS scores a good deal ahead of the rest of the region and the teams have come the closest to cracking Mexico's dominance. But on average they are still a goal per game behind the greatest soccer country in the region. Fans will be suprised to see MLS just behind Ascenco MX

2. Mexico - Ascenco MX (-0.9 Tournament GDI, 0.0 depth adjustment, Total GDI -0.9)

Ascenco teams perform very closely to Liga MX teams during the Copa MX, much better than other countries do in the Champions League. That is partly due to the fact that Liga MX CCL teams do not compete in Copa MX, but that has been adjusted for in the goal difference index. Strong surges from Ascenco MX to Liga MX like Tijuana and Leon in the past couple of years only strengthen the argument.

1. Mexico - Liga MX

No surprise in this unveiling. Liga MX boasts the last nine CONCACAF Champions League trophy winners and 17 of the last 24 semifinalists (not including the most recent CCL semifinals). It will be a long while before MLS can go toe to toe with Liga MX. Liga MX is the showcase league for the confederation and the anchor by which Don Garber will be measured in the states.

If you are curious you can view a detailed breakdown of the methodology behind the GDI here.