Dafydd Pritchard
BBC Sport Wales in Baku

Baku Olympic Stadium is an impressive 68,700-capacity ground which hosted last season's Europa League final and will be one of the venues for Euro 2020.

But tonight's Euro 2020 qualifier between Azerbaijan and Wales is playing played at the smaller, more modest Bakcell Arena.

This is also a new stadium - opening in 2012 - but it holds only 11,000 people.

Image source, BBC Sport

Scotland have just beaten Cyprus 2-1 in a dead rubber. Read the report here if you care.

Dafydd Pritchard
BBC Sport Wales in Baku

Azerbaijan boss Nikola Jurcevic makes three changes from the 1-0 defeat in Hungary in October. Anton Kriovtsyuk, Araz Abdullayev and Dmitri Nazarov replace Eddy Israfilov, Agabala Ramazanov and Tamkin Khalilzade.

Azerbaijan XI: Balayev; Pasayev, Mustafazade, Huseynov, Krivotsyuk; Garayev, Almeyda; Abdullayev, Nazarov, Rahimov; Sheydaev.

Dafydd Pritchard
BBC Sport Wales in Baku

Image source, .

Wales manager Ryan Giggs makes three changes from last month’s 1-1 draw against Croatia. Juventus midfielder Aaron Ramsey, who has not yet featured in this qualifying campaign, is only on the bench after returning from injury.

So Joe Morrell comes in for the suspended Joe Allen in midfield. Centre-back Joe Rodon and midfielder Jonny Williams are out injured and replaced by Chris Mepham and Harry Wilson.

Gareth Bale captains the side again with Ashley Williams on the bench.

Wales XI: Hennessey; Roberts, Mepham, Lockyer, Davies; Ampadu, Morrell; Bale, Wilson, James; Moore.

Do you think Wales or Northern Ireland will qualify for Euro 2020? Do you understand the play-off system at all?

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Anyway, that's enough permutations chat for now. Let's look ahead to the actual football. We'll preview Wales' game now and then Northern Ireland's nearer the time. Makes sense, right?

Image source, .

Northern Ireland's hopes are a lot slimmer.

They need to beat the Netherlands at home (19:45 GMT today) and Germany away on Tuesday in their final two games by a cumulative total of at least four goals.

If they win both games 1-0, they would need either the Germans or the Dutch to slip up in home matches against Belarus and Estonia respectively.

Michael O'Neill's side will be in the play-offs next March if they fail to finish in the top two.

If Northern Ireland fail to beat the Netherlands and Germany beat Belarus, then the Dutch and Germans will qualify for next summer's tournament tonight.

So Wales' hopes will be in their own hands if they beat Azerbaijan today and Croatia don't lose at home to Slovakia tonight (19:45 GMT).

In effect, Wales' game against Hungary in Cardiff on Tuesday (19:45) would be a winner-takes-all showdown.

Image source, .

Wales, despite sitting fourth, still have a reasonable chance of qualifying.

If they beat Azerbaijan away today (17:00 GMT) and Hungary at home on Tuesday - and Slovakia drop points against either Croatia or Azerbaijan - then Ryan Giggs' side will reach Euro 2020.

Defeat in Baku on Saturday would end their hopes of automatic qualification, although they have the fall-back of a play-off place next March.

Croatia will qualify if they draw against Slovakia tonight at 19:45 GMT, but Hungary and Slovakia's hopes will go down to the final day.

The bad news: Even wins in the final two games might not be enough to take them to Euro 2020.

The good news: Wales and Northern Ireland are both guaranteed a Euro 2020 play-off place next March at the very least - and could yet qualify automatically.

Do you want the good news or the bad news first, Wales and Northern Ireland fans?