The first part of this series outlines how the race is run, who is agitating, and what their interests are. Part 2 will handicap the field of early secretary-general contenders, from a 39 year-old Montenegrin wunderkind to Australia's own Kevin Rudd.

Eurasia Group's Ian Bremmer recently warned about the absence of global leadership, claiming that we've reached a 'G-zero world' in which global caucus members don't share political or economic values or a common vision for the future. It's against this backdrop that world leaders will this year select the next UN Secretary-General (SG) to replace Ban Ki-moon when his second term ends on 31 December.

This year's SG race features record levels of public engagement with the candidates, intense lobbying from civil society groups, and the potential for geopolitical clashes. Below are the key issues to follow as the process unfolds throughout 2016.

There is an unprecedented push for reform underway…

The SG selection process has long been considered secretive and undemocratic, and reform advocates calling for more openness and inclusion are gaining momentum this time. The UN Charter stipulates only that the SG 'shall be appointed by the General Assembly upon the recommendation of the Security Council,' leaving the rest of the process to be decided by custom and informal agreements. In practice, the Council — most importantly the permanent five (P5) members who hold veto power — almost always recommends a candidate, and the General Assembly serves as a rubber stamp. The SG race tends to play out differently each time, reflecting both evolving UN practices and occasions when SGs have resigned or died while in office, and it looks like this will be the case again this year (for more information, see Security Council Report's special research report and the Center on International Cooperation's online magazine guide).

Led by an alliance of NGOs known as 1 for 7 billion, SG reform advocates have been lobbying for various changes including: a formal nomination process with clear deadlines and job qualifications; a single, non-renewable, seven-year term; engagement with the candidates; and for the Security Council to nominate more than one candidate. Bowing to the calls for reform, the presidents of the Security Council and the General Assembly issued a joint letter in December 2015 soliciting candidates and offering opportunities for informal dialogues and meetings. This was the first time the UN has officially kicked off the selection process. Critics say it's a small improvement in a largely broken system.

…but transparency can be a double-edged sword.

While transparency is generally presented as a good thing, it's worth considering the risks. Former senior UN official Alvaro de Soto argues that the process has evolved from one where the Security Council sought out potential SGs — former SG Dag Hammarskjold famously didn't know he was being considered — to one in which candidates seek the job. In exchange for support, candidates are now expected to make promises and horse-trade favours, undermining their independence even before they assume the role.

Additional exposure of candidates also risks hampering the Council's decision-making process as it seeks to find not only the best candidate, but one who is acceptable to each of the veto-wielding P5 members. For example, questioning candidates publicly on controversial issues, such as the conflict in Ukraine, could push them to make statements that would render them toxic to one P5 member or another.

De Soto also warns that thrusting SG nominees into the limelight can call attention to the wrong attributes of a candidate. He writes:

Public grillings of candidates may bring out the skills of a successful politician or communicator or CEO. But they won't tell us whether the candidate has the temperamental profile, the empathetic skills, the coolness of mind and the experience of performing diplomacy of that rarefied kind: the third party role in solving conflict.

Regional rotation is not a fixed rule but nationality matters.

UN member states continue to debate the value of geographic diversity and the much-touted concept of a regional rotation for the SG post. Neither is mentioned in the UN Charter, and the actual timeline of SG terms doesn't establish a clear pattern of rotation. Furthermore, the history of candidates considered from various regions during most races suggests that regional rotation is not as entrenched as political commentators might make it seem.

On the other hand, UN General Assembly resolutions have referenced geographical balance, and the perception of an informal regional rotation continues to resonate with many UN member states. Regional groups, sometimes with the support of P5 members, have succeeded in establishing a sense of inevitability around their candidates in the past. The Eastern European Group, the only UN regional group that hasn't held the SG post, has Russia's support and has made remarkable progress in building consensus around the idea that it's Eastern Europe's turn this time around.

Some rotation advocates have suggested that the Western European and Others Group (that includes Australia and New Zealand), which hasn't had an SG for 35 years, would be next in line if the Council fails to agree on an Eastern European. However, the Latin American and Caribbean Group also has a case to make for under-representation at the helm of the UN, as it has only held the post for two terms while the others have had at least three. A Latin American candidate may have a better chance of making it past the P5, given ongoing tensions between Russia and the West.

Female candidates are in high demand

After 70 years of male SGs, many UN observers, including civil society groups like WomanSG and Equality Now, are calling for a female UN chief. More than 40 UN member states have signed a document promoting the selection of a woman, and the UN's recent joint letter encouraged member states to consider presenting women, as well as men, as candidates. Some member states are calling for the most qualified candidate regardless of gender or nationality, while others argue that it's high time for a woman, not only to demonstrate the UN's commitment to gender equality and to empowering women, but also to bring a more diverse perspective to its leadership.

The P5 remains the ultimate decision-maker

Despite the steps taken to make the SG selection process more open, and the calls for further reforms, the candidates' chances are still largely determined by the P5. This race provides an opportunity for Russian obstructionism, as Moscow's views will be particularly critical in the consideration of Eastern European candidates. Russia's outspoken UN Ambassador claims that Moscow supports an Eastern European woman, although he had previously stated that the candidate should be chosen based on merit alone.

The race also represents a chance for the Obama administration to leave its mark on the organisation before leaving office, just as the Bush administration did in 2006 — former US Ambassador to the UN John Bolton claims in his book that then US Secretary of State Condoleezza Rice told him, 'I'm not sure we want a strong secretary general'. France in the past has insisted on the SG speaking French, although Ban's struggles with the language suggest that Paris has backed down from strictly enforcing its own informal tradition.