The smiles for Marcus Epps and his Union teammates at home last Wednesday
quickly evaporated in a road loss to New England Saturday. (AP)

Discussion around the Union last week followed a predictable tack. After three straight road contests and no wins, the latest a punchless performance in Columbus, the Union returned home to thoroughly dominate the Crew, then again pulled up stakes for New England only to be routed in similar fashion.

The trends were so obvious as to warrant discussion in Jim Curtin’s two press addresses: That the Union have excelled at home yet failed to translate that form into anything close on the road. The path to the postseason for the Union (7-10-5, 26 points) is quite clearly laid out. With 18 available points in their six remaining home games and 44 points likely insufficient to earn the sixth and final playoff berth, the Union need to be spotless at home the rest of the way and steal a couple of results away from home. That’s a lot of questions about “must-wins” headed the way of Curtin and his players in the next couple of months.

There’s another way to look at that conundrum, beyond the cold standings arithmetic. The Union in 2017 have one away win, a 4-0 stomping of 10-man and last-place D.C. United May 13. The club has three times lost at Talen Energy Stadium – April 8 to Portland and April 14 to New York City FC as part of the eight-game winless streak that stopped the season’s progress before it really started; then June 18 to the Red Bulls thanks in part to Derrick Jones’ red card.

That ratio, of road wins to home losses (let’s call it RW/HL), isn’t much talked about in MLS (or really anywhere). But it’s a potent determinant of playoff fate.

The big advantage

Home-field advantage in MLS is a much talked about concept, one that is more pronounced than in other leagues worldwide. Some of the reasons are obvious. Take the English Premier League, for instance, which draws its teams from a country roughly the size of Alabama (notwithstanding the Welsh clubs, Swansea City and Cardiff City). In any given year, five or six teams hail from Greater London, which means that a London club will have only a dozen or so true “away” games. One cross-country flight in MLS can cover more miles in a weekend than a Premier League club will log all season.

MLS offers teams greatly varied climates – contrast Toronto in November with Houston in July – different playing surfaces, variable field dimensions and sundry other challenges. The long and short of it is that winning on the road in MLS, not easy.

That reality imbues special significance not just on getting three points at home whenever possible but preventing marauding visitors from leaving your place with three points.

There’s plenty of debate about this across most sports, but rarely does it look directly at the ratio of home losses to road wins. (There’s some discussion in NBA circles, but I found little elsewhere, though home winning percentage certainly is a universal analysis in American sports.)

The golden ratio?

MLS presents an interesting case study. The schedule is moderately balanced, and results aren’t skewed either by scarcity of games in the NFL or abundance in Major League Baseball. Draws aside, three points gained or lost have the greatest impact on the standings.

So what does recent MLS playoff history tell us? Since 2011, when the league normalized its playoff composition to admit equal numbers from the Eastern and Western Conferences, your playoff fate can often be predicted by your ratio of wins on the road to losses at home. Take a look at the data for yourself.

In six seasons, 64 MLS teams have qualified for the playoffs; 56 had as many or more road wins than home losses. That’s 87.5 percent of the playoff teams with a positive RW/HL. From 2012-15, only one team made the playoffs with more home losses than road wins (Toronto in 2015).

The same holds true for the 51 non-playoff teams over the same span. Only six teams that failed to make the playoffs had a positive RW/HL, meaning that 88.2 percent of non-playoff qualifiers had a negative RW/HL. (Of the six non-qualifiers, five finished one spot outside of playoff placements.)

The rule isn’t perfect – in 2016, for instance, five playoff qualifiers accumulated a negative RW/HL, three in a historically week East. But the converse still held true in that all eight non-playoff sides held negative RW/HLs.

How does the analysis track this year? As of the weekend’s games, 11 of 12 teams in playoff position have a positive RW/HL; the 12th team is Columbus, which has three road wins against three home losses. Of the 10 teams outside the playoff picture, San Jose is the only one without a negative RW/HL.

2017 MLS road win/home loss ratio (through July 30)

This ratio may not be predictive as much as reflective of the obvious: Teams that don’t lose at home generally get to the playoffs, and teams that are strong on the road are generally those elite teams. There’s no huge secret embedded therein, and there’s no implicit blueprint to recommend, say, whether a coach faced with a Saturday-Wednesday-Saturday turnaround should target an easy home game at the expense of a difficult road test beyond what he already knows about the travails of gleaning road results in MLS.

It’s not exactly MLS’s answer to nature’s golden ratio. But it’s yet another way to appraise teams’ playoff candidacy.