First you have the skin. okay that analogy doesn't work as well with the UEFA Nations League as it does for marriage, but the point remains that this new competition - one which has been decried as complicated and convoluted - is actually very, very simple.
Ahead of the opening games, we have detailed how it will be formatted, when the matches will take place and why results will matter. Let's start off with the basics.
But the real incentive is that the Nations League offers an alternative path to secure a place at Euro 2020, a second-chance saloon, if you like.
It starts in September and continues across the October and November global breaks.
Instead of starting directly following the World Cup as it had in previous years, qualifying for Euro 2020 will now begin in March 2019 and run until November 2019.
What is the tournament format?.
Created to limit the number of friendly matches - although there will still be some in the fixture list - the new competition places all 55 nations recognised by UEFA into four separate leagues based on pre-World Cup 2018 rankings, and within these leagues teams will be placed into groups of either 3 or 4 and play one another home and away.
Xherdan Shaqiri is part of the Swiss team for that game at the home of Leicester City and the Nations League encounter with Iceland which precedes it.
The winners of Group B, C and D will win promotion, while those who finish bottom of Groups A, B and C will be relegated.
Embattled blood-testing firm Theranos to dissolve
Theranos , with Holmes at the helm, had claimed that it could run a slew of physiological tests with a simple pin-prick of blood. In March, Ms Holmes settled charges with the Securities and Exchange Commission, a top U.S. financial regulator.
Northern Ireland, Slovakia, Sweden, Ukraine, Bosnia and Herzegovina, Czech Republic, Turkey, Austria and Russian Federation make up the remaining nine sides in League B.
The four group winners in League A, however, will qualify for the Uefa Nations League Finals set to be played in June 2019, in one of the participating countries.
When will Nations League matches be played?
Reds striker Dominic Solanke has been called up by England U21s for European Championship qualifiers with the Netherlands (Thursday September 6) and Latvia (Tuesday September 11).
For instance, England are in League A, and have been drawn into Group A4. Northern Ireland play Bosnia on Saturday (September 8) at Windsor Park.
League B - features the Republic of Ireland..
UEFA's competition gets more confusing for teams who don't qualify for the Euros in 2020 because there is a route to the competition for those whose traditional qualifying campaign goes array. They will take place from March to November 2019, with a draw to be held this coming December.
The winners of the four League A groups will be drawn into the play-off finals. That will account for 20 of the finalists. The countries will be divided into their four leagues, each of which will include two single-legged semi-finals and a one-off final.
The decision to introduce a third competition could be made as early as September 27, when the UEFA executive committee meets in Nyon to decide on the hosts of the 2024 European Championship. Should any of the league winners have already qualified through qualifying, they are to be replaced in the playoffs by the next-best ranked team in their league.