Who will succeed Michelle Bachelet in Chile?

Sebastián Piñera (L) and Alejandro Guillier are neck and neck in the opinion polls

Once there were eight, now there are two. As Chileans vote in the second round of the presidential election on Sunday, they will now have a straight choice.

And, in a way, both candidates could be said to represent continuity.

The frontrunner in the first round, billionaire businessman Sebastián Piñera, already governed the country from 2010 to 2014.

And second-placed Alejandro Guillier has the endorsement of the current socialist president, Michelle Bachelet, and has promised to continue many of her policies.

While the campaign has been rather sluggish, the second round will be closely watched in the region to see if it results in another loss for left-wing parties in Latin America.

A decade ago, Argentina, Bolivia, Brazil, Chile, Cuba, Ecuador, Honduras, Nicaragua, Uruguay and Venezuela were all governed by left-wing leaders.

But in recent years, conservatives have come to power in Argentina, Brazil and Paraguay, and Venezuela's "Bolivarian Revolution" has come under severe pressure with anti-government protesters taking to the streets for months.

A win by Mr Piñera and his Chile Vamos coalition would further consolidate that trend.

How likely is a rightward swing?

Sebastián Piñera won by a wide margin in the first round

The most recent opinion polls suggest that Mr Piñera has a slight lead over Mr Guillier, but it is slim at only 1.4 percentage points.

In the first round, Mr Guillier, a former journalist and news anchor, came in a distant second behind Mr Piñera with 22.7% compared to the billionaire's 36.6%

But Mr Guillier is expected to pick up the votes cast in round one for the left-wing candidate Beatriz Sánchez.

While Ms Sánchez was hesitant to endorse Mr Guillier at first, she asked her supporters to vote for him after Mr Piñera suggested some of the votes cast for her and Mr Guillier had been fraudulent.

If the hitherto divided left-wing unites behind Mr Guillier he could beat Mr Piñera.

A right-wing swing in Chile is therefore not a given.

What do the candidates stand for?

Mr Guillier was facing an uphill battle after trailing Mr Piñera by almost 14 points in the first round

Mr Piñera has promised to rein in the reforms brought in by President Bachelet, saying he will halt the expansion of free university education and make modifications to pensions and taxes.

Mr Guillier, on the other hand, has campaigned on the back of President Bachelet's legacy, vowing to boost regional investment and shore up the welfare state.

Is President Bachelet's legacy on the line?

President Bachelet hopes Mr Guillier will continue many of her policies

While President Bachelet's progressive agenda has won plaudits abroad, her popularity plummeted during her second term, due in part to a 2015 corruption scandal involving her daughter-in-law.

This year, however, the president overcame conservative opposition to successfully ease Chile's strict anti-abortion laws.

Conservative critics say Ms Bachelet pushed her reforms too far, while some voices on the left accuse her of losing touch with the people.

Even Mr Guillier, who is endorsed by Ms Bachelet's coalition, says Chileans are demanding "real change" and "reforms that reach regular people".

What is in store for the winner?

There have been clashes between the Mapuche indigenous group and the security forces.

Both Mr Piñera and Mr Guillier say that, if elected, they will diversify external trade to ease Chile's dependency on its main export, copper.

Economic growth in Chile is lagging behind that of other Latin American nations and analysts say a future dip in copper prices could cause problems for whoever comes to power.

Tensions with indigenous communities in the southern Araucania region could also cause headaches for the incoming president, with reports of unrest on the rise.

What could it mean for the region?

Chile has granted asylum to Venezuela opposition politicians and Supreme Court justices

The Bachelet administration stepped up its role in the Venezuelan political crisis recently by offering asylum to Venezuelan opposition figures.

A victory for the right in Chile would only deepen the rift between the two countries.

Likewise, Chile's growing impatience with Bolivian leader Evo Morales would certainly solidify under Mr Piñera's leadership.

On the other hand, relations with Argentina would likely become closer under Mr Piñera as he has often expressed his admiration for the Argentine leader, Mauricio Macri.

Further afield, Chile's economic dependence on China and the United States suggests a pragmatic foreign policy approach.

A newly-signed update to Chile's free trade deal with China, as well as the former's presence in the Trans-Pacific Partnership, mean any incoming president will probably continue looking to Asia for much of the country's trade.