Uefa's newest international football tournament - the Nations League - begins on Thursday with many fans wondering what it's all about. The tournament is an attempt by European football's governing body to address the amount of meaningless friendlies that would often pair together minnows against the continent's elite in lopsided affairs in the middle of domestic seasons. It is also meant to sate the appetite of football fans dreading a non-tournament summer in between World Cups and European Championships as well as offer some nations who do not qualify for Euro 2020 via the normal route a path to the play-offs. The idea that international managers will need to pick competitive squads for competitive matches, instead of making wholesale changes for second half of international friendlies where the results matter little, is not necessarily a bad one, although clubs have been less than enthused by it. The thought of players in competitive action for their country so soon after the World Cup might have something to do with it, but the thought of say, England, taking on a powerhouse like Spain and Croatia with something at stake rather than a friendly against Gibraltar that doesn't, should keep fans interested. Another gripe among club bosses is that it means extra games on the international calendar. It doesn't. Nations League matches only replace aforementioned meaningless friendlies. <em>The National</em> explains everything you need to know about the tournament, how it works, key dates and the ramifications for the Euro 2020 play-off system. All European countries have been seeded in four pots according to their coefficient ranking, not their Fifa one (don't ask). There are 55 teams taking part, so a fair few fixtures to work through. France, the world champions, are in League A alongside Croatia, whom they vanquished in July's World Cup final in Moscow, along with semi-finalists in Russia Belgium and England. Portugal, Spain, Switzerland, Poland and Iceland - who also played at this summer's World Cup - are also included, alongside traditional European powerhouses Italy and Netherlands, both of whom failed to qualify for Russia. See the panel on the left for Leagues B, C and D. Leagues A and B will consist of four groups of three teams who will play each other home and away. League C will feature one group of three teams and three groups of four teams. The teams play each other home and away. League D is made up of four groups of four teams playing each other home and away. Each league has a path of its own, and will consist of two single-leg semi-finals and a one-off final. Winners of the mini-groups of three in League A will compete in June 2019 semi-finals and ultimately the final on June 9 for the Nations League trophy. <strong>League A groups:</strong> Teams that finish at the bottom of League A are relegated to League B. They are all competing for promotion and relegation, so winners of Group B, which on paper could look like Ukraine, Russia, Northern Ireland and Denmark, would play for the chance to take on the top nations next year. <strong>League B groups</strong> <strong>League C groups</strong> <strong>League D groups</strong> <strong>_______________</strong> <strong>Read more:</strong> <strong>Ronaldo ricochet and pricey goalkeepers: <a href="https://www.thenational.ae/sport/football/ronaldo-ricochet-and-pricey-goalkeepers-european-transfer-window-talking-points-1.765659">European transfer window talking points</a></strong> <strong><a href="https://www.thenational.ae/sport/football/bale-can-fill-ronaldo-boots-at-real-says-wales-manager-giggs-1.765148">Bale can fill Ronaldo boots at Real, says Wales manager Giggs</a></strong> <strong><a href="https://www.thenational.ae/sport/football/fifa-looks-for-25-billion-12-year-deal-for-new-tournaments-1.720921">Fifa looks for $25 billion, 12-year deal for new tournaments</a></strong> <strong><a href="https://www.thenational.ae/sport/football/uefa-nations-league-exciting-for-england-football-manager-gareth-southgate-1.698461">Uefa Nations League exciting for England football manager Gareth Southgate</a></strong> <strong>_______________</strong> Yes. The Euro 2020 qualification draw takes place in Dublin in December with all the matches due to be played between March and November 2019. The top two teams from 10 groups will automatically qualify for the finals. That will account for 20 of the finalists. The final four places are where the Nations League comes in again. According to Uefa's website, the equation for qualifying for Euro 2020 is now <a href="https://www.uefa.com/uefanationsleague/news/newsid=2079553.html">"simple"</a>, although that's debatable. Yes. The four group winners from each league - A, B, C and D, so 16 teams in all - will play off in March 2020 in a bid to secure one of the four remaining places. The format will be one-off play-off semi-finals, followed by a final, per league, with the winning team from each of leagues A, B, C and D taking the last four spots at the Euros. If a country has already qualified by the conventional route, their place will go to the next highest-ranked team from their respective Nations League tier. Confused? Us too. But it should be fun trying to figure it out. <strong>Matchday 1: </strong> <strong>September 6, 2018</strong> <strong>Friday, September 7 </strong> <strong>Saturday, September 8</strong> Matchday 2: <strong>Sunday, September 9 </strong> <strong>Monday, September 10</strong> <strong>Tuesday, September 11</strong> <strong>Matchday 3:</strong> <strong>Thursday, October 11</strong> <strong>Friday, October 12</strong> <strong>Saturday, October 13</strong> <strong>Matchday 4:</strong> <strong>Sunday, October 14</strong> <strong>Monday, October 15</strong> <strong>Tuesday, October 16</strong> <strong>Matchday 5:</strong> <strong>Thursday, November 15</strong> <strong>Friday, November 16</strong> <strong>Saturday, November 17</strong> <strong>Matchday 6:</strong> <strong>Sunday, November 18</strong> <strong>Monday, November 19</strong> <strong>Tuesday, November 20</strong>