Four scenarios for Myanmar's crucial vote

Supporters of Myanmar opposition leader Aung San Suu Kyi listen as she speaks during a campaign rally for the National League for Democracy in Yangon on 1 November 2015. Image copyright AFP
Image caption The National League for Democracy led by Ms Suu Kyi is the frontrunner in the election

Myanmar has held its first openly contested general election for 25 years. Many expect the party of former political prisoner Aung San Suu Kyi to win the most seats but, as the BBC's Jonah Fisher in Myanmar explains, that doesn't mean it will come out on top.

Sunday's vote was the first time since 1990 that Aung San Suu Kyi's National League for Democracy (NLD) has competed in a nationwide vote, but the constitution has been designed to constrain and control the outcome. The Burmese army calls it "disciplined democracy".

Twenty-five percent of the seats in parliament are reserved for the military, and the key security ministries are nominated not by the president but the army's commander-in-chief.

Whatever the result the army will still be extremely powerful and Aung San Suu Kyi is blocked from becoming president. In fact, we are unlikely to know who Myanmar's next president is before February.

Image copyright AFP
Image caption The army backs the ruling Union Solidarity and Development Party (USDP)

The top job isn't chosen by popular vote but indirectly by parliament - a complex process which will culminate with both houses choosing between three presidential candidates.

To be certain of putting their man or woman in the presidency the winning party will need half the MPs but, with three in the race, as little as 40% might be enough.

And the reason we know it won't be Ms Suu Kyi is Clause 59F. This stipulates that anyone with foreign children is ineligible to become president and as she has two British sons that rules her out.

However big an NLD landslide, if the army wants to keep that clause it simply can't be changed. But these are some of the scenarios that could unfold.

1. An Aung San Suu Kyi landslide gives her control of the presidency

Image copyright AP
Image caption Ms Suu Kyi is barred from becoming president

To achieve this the NLD needs to win two-thirds of all the contested seats. It's a big ask and will only be achieved if it wins large numbers of seats outside the areas dominated by the ethnic Bamar, the dominant group in Myanmar.

As Ms Suu Kyi can't become president, she says she will nominate someone else and still lead the government, probably from the position of Speaker of the house.

This option appears the most clear cut, but it could also prove problematic.

Some may see Ms Suu Kyi overtly controlling a puppet president as unconstitutional.

There is also the possibility that, emboldened by a big win, she will push hard for greater reform and constitutional change. That is likely to lead very quickly to confrontation with the army.

In August, when the Burmese military felt it had lost control of the ruling USDP party, it helped engineer a "soft coup" and a change of leadership. The possibility of that happening at a national level should not be discounted.

Image copyright Reuters
Image caption Shwe Mann used to head the USDP until he was ousted

2. Aung San Suu Kyi wins but not by enough

This is essentially a scenario where she fails to get a parliamentary majority.

If the NLD fails to win the required two-thirds of the contested seats, they will have to reach out to "friendly" ethnic parties. This should be relatively straightforward, though relations have been strained by the NLD's decision to run candidates in ethnic minority areas.

The NLD choice for president would then have to be approved by the smaller parties.

3. Aung San Suu Kyi wins most seats but does not have enough support

Image copyright AFP
Image caption Twenty-five percent of the seats in Myanmar's parliament have been allocated to the military

The most complex scenario.

Aung San Suu Kyi's party win the most seats, but a coalition of the USDP, some ethnic parties and the 25% of the army enables the military candidate to take the presidency.

That would almost certainly mean a second term for incumbent President Thein Sein, and could be achieved even if his party takes as little as 15% of the seats.

Constitutionally it would be a legal and fair result, but it would hardly feel like democracy in action.

Much would then hinge on the likely negotiations between Ms Suu Kyi and Thein Sein.

If Ms Suu Kyi felt that there was little prospect of constitutional change, she could lose patience with a parliamentary system that is rigged against her.

Some think a deal has already been done. There are those who believe Ms Suu Kyi has agreed to Thein Sein staying on for a shortened period, perhaps two years with the promise of constitutional reform.

4. The USDP wins the most seats

This is an option so unlikely that most would immediately assume that the results had been rigged. Ms Suu Kyi's party would almost certainly walk out of parliament.