Still confused by the Nations League? Here's your ultimate guide to the new tournament ahead of big kick-off.
England's campaign in the first UEFA Nations League gets under way on Saturday when they take on Spain at Wembley.
UEFA have introduced this tournament to give national teams more competitive matches and fewer meaningless friendlies.
It has a group stage, a final tournament and a trophy for the winner.
The 55 European countries have been split into four leagues — A, B, C and D — based on their UEFA ranking.
As England are one of the 12 best - ranked sides, they are in League A.
Each league has been split into four mini-groups, with England pitted against Spain and Croatia in Group 4.
Gareth Southgate's side will face both teams home and away between now and November, starting with the Spanish at Wembley on Saturday.
Top the group and England will advance to the Nations League finals with the three other group winners from League A.
In December, one of these four will be picked to host the final tournament.
In June 2019, the teams will take part in semi-finals and a final to crown the first Nations League champions.
Finishing bottom would see England relegated to League B. For the likes of Wales and Northern Ireland who are in League B this year, winning their mini-group would mean promotion to League A.
They can. Four teams will qualify via the Nations League play-offs and join the 20 teams who will take their places for Euro 2020 through a qualifying group as normal.
The four mini-group winners from each of the Nations League tiers — A, B, C and D — will contest a one-off semi-final, followed by a final, in March 2020.
The winners of the play-off final in each of the four leagues will then qualify for Euro 2020.
It means that if England beat Spain and Croatia to the top of their mini-group this autumn, they could still go on to claim a play-off place for Euro 2020 even if they mess up in their qualifying campaign next year.
If England win their Nations League group this autumn but also finish in the top two of their qualifying group next year, their play-off place will go to the next best Nations League side who have not already qualified.
NATIONS LEAGUE - THE GROUPS:
The Nations League trophy, which will be contested in summer 2019 by the four teams who top their groups in League A.
Group A1: Germany, France, Netherlands
Group A2: Belgium, Switzerland, Iceland
Group A3: Portugal, Italy, Poland
Group A4: Spain, England, Croatia
Group B1: Slovakia, Ukraine, Czech Republic
Group B2: Russia, Sweden,Turkey
Group B3: Austria, Bosnia and Herzegovina, Northern Ireland
Group B4: Wales, Republic of Ireland, Denmark
Group C1: Scotland, Albania, Israel
Group C2: Hungary, Greece, Finland, Estonia
Group C3: Slovenia, Norway, Bulgaria, Cyprus
Group C4: Romania, Serbia, Montenegro, Lithuania
Group D1: Georgia, Latvia, Kazakhstan, Andorra
Group D2: Belarus, Luxembourg, Moldova, San Marino
Group D3: Azerbaijan, Faroe Islands, Malta, Kosovo
Group D4: FYR Macedonia, Armenia, Liechtenstein, Gibraltar
