When Major League Soccer returns from a four-month coronavirus layoff, its 26 teams will gather in Orlando for a tournament whose format is fundamentally unfair.
A design flaw will tilt the playing field against six of the 26 teams before the competition even begins.
Structurally, each of those six teams — Orlando City, Inter Miami, NYCFC, Philadelphia Union, Chicago Fire and Nashville — has a less than 50 percent chance of advancing to the knockout stage.
Each of the other 20 teams has a greater than 65 percent chance of advancing.
Here’s where MLS seemingly went wrong, and how it could fix the flaw with a simple adjustment.
The problem with MLS’ format
No 26-team tournament can be completely balanced. MLS’ plan to accommodate the awkward number was to use a typical 24-team format — six groups of four, then a 16-team knockout round — and simply add two teams to one group.
Thus, we have:
Like at the Women’s World Cup, the top two teams from each group will advance to the knockout stage, along with the four best third-place teams. And that’s where the six-team group becomes problematic.
Group A will send either 33 percent or 50 percent of its teams to the knockout stage. Every other group will send either 50 percent or 75 percent of its teams.
The math is complex, but a given Group A team — say, the Philadelphia Union — has around a 48 percent chance of qualifying for the knockouts. A given non-Group A team — say, the New England Revolution — has around a 66 percent chance.
Below is one breakdown a reader passed along, with the acknowledgement that it exaggerates the disparity slightly. (The probability that the third-place Group A team is among the four best third-place teams is, in actuality, greater than 66.67 percent. The above calculations estimate it at 90 percent, with the qualification probability for each of the other five third-place teams at 62 percent.)
Those probabilities, of course, don’t account for team quality. But the draw was largely unseeded. MLS placed Orlando and Miami, as host and host’s rival, into Group A intentionally. The other four were randomly drawn, and thus dealt a disadvantage without doing anything to deserve it.
How MLS could fix the error
To some, this is a minor qualm. But the tournament stakes are significant: a $1.1 million prize pool and a CONCACAF Champions League berth. The difference in knockout round probabilities is significant as well. And, perhaps most importantly, there’s a simple fix.
Rather than give the 16 knockout berths to six group winners, six runner-ups and four third-place teams, MLS could tweak that allocation to:
Six group winners
The third-place team from Group A
The three highest point-earners out of A) the other five third-place finishers, and B) the fourth-place team from Group A
In other words: the top 50 percent of each group should qualify automatically. And then of the next-best teams in each group, the top three should qualify as well.
The adjusted format would give an average Group A team, roughly, a 59 percent chance of advancing and a non-Group A team, roughly, a 62 percent chance. It would close the probability gap between Group A and the rest from around 18 percentage points down to 3.
Below is the analogous math breakdown – again with the caveat that the fourth of six in Group A will, on average, finish with more points than the third of four in a normal group. So the probability of Group A sending four teams is slightly higher than depicted here.
And here – via American Soccer Analysis’ predictive data, factoring in team strength – is a more scientific look at the imbalance of the current format vs. the relative equity of the proposed solution:
Consequences of the flawed format
Put another way: Finishing top-four in a six-team group is more impressive than finishing top-three in a four-team group. Yet under the current format, the team that finishes fourth in the six-team group can’t advance; at least three of the five who finish third in their four-team groups will advance. That’s backwards.
In fact, under the current format, there’s a realistic scenario where a Group A team on six points gets left out of the knockout round in favor of a team on one or two points:
It’s unclear whether MLS recognized this flaw, or whether it considered fairer alternatives. The league did not respond to a request for comment.
The tournament begins July 8.
More from Yahoo Sports: