Guessing the winner of the Nobel Peace Prize is notoriously hard because the secretive Norwegian Nobel Committee isn't dropping any hints, except that 376 people and groups have been nominated for the award, which will be announced on October 7.
That doesn't stop Nobel watchers from speculating, sometimes based on their own preferences or the small number of nominations that were made public by those who submitted them.
This year they include Pope Francis, the Afghan women's cycling team, former National Security Agency contractor Edward Snowden, the White Helmets rescue group in Syria and Nadia Murad, a Yazidi woman who escaped sexual slavery and has become a spokeswoman for those abused by Islamic State militants.
One way to get a sense of potential winners is to look at the committee's previous choices. An Associated Press analysis of the past 30 winners found they typically fit into five different categories:
Former foes
Opposite sides of a violent conflict sitting down to make peace - it's hard to find anything that better embodies the spirit of the Nobel Peace Prize.
Yet winners in this category are surprisingly few. The last time the committee awarded that type of prize was in 1998 when it went to John Hume and David Trimble, the leaders of Catholic and Protestant parties that negotiated a peace agreement in Northern Ireland.
Former foes can be a risky choice because sometimes they remain foes and their peace deal falls apart, like the Oslo Accord between Israelis and Palestinians that inspired the 1994 peace prize.
Should the committee dip into this category, the most obvious candidates this year would be Colombian President Juan Manuel Santos and the top commander of the country's FARC rebels, Rodrigo Londono, who just recently entered a peace deal with the help of Norwegian mediators.
Another alternative could be last year's Iran nuclear deal. Possible candidates for that include U.S. Secretary of State John Kerry and Iran's Foreign Minister Javad Zarif, or the chief negotiators on both sides.
Dissidents
Political prisoners or exiles engaged in a non-violent struggle against an authoritarian regime are among the most memorable picks of the Nobel committee.
Examples include 1991 winner Aung Sang Suu Kyi, who stood up against the military rulers of Myanmar, and Iranian human rights activist Shirin Ebadi, who won in 2003. The most recent dissident prize was in 2010 when the committee infuriated China by choosing jailed activist Liu Xiaobo.
If the committee fancies another dose of controversy it could give the prize to Snowden, who is considered a dissident by some for leaking information on secret U.S. surveillance programs and fleeing to Russia.
Raif Badawi, the Saudi blogger who was jailed and flogged in 2012 for insulting Islam, could be another contender in this category.
Institutions
Accounting for almost one-third of the winners in the last 30 years, institutions tend to cleave close to the original thinking behind the peace prize.
Award founder Alfred Nobel stressed fraternity between nations, arms reduction and the setting up of peace congresses as his key metrics. Prizes to the European Union in 2012 and the Organization for the Prohibition of Chemical Weapons in 2014 fit the terms he left in his will.
Sometimes, the committee splits the prize between an institution and its leader or an individual championing the same cause, like the 2007 award shared by the Intergovernmental Panel on Climate Change and Al Gore.
With 148 institutions nominated this year, picking a preferred candidate is near impossible. But few would begrudge a win for Save the Children, which has worked in refugee camps in and around Syria to provide food and comfort to hundreds of thousands of minors displaced by the war.
Should the judges want to honor last year's hard-fought Paris Agreement on climate change, without singling out any one country or leader, a safe choice would be the U.N. secretariat that supported the negotiations.
Statesmen
Dominating this category are presidents and prime ministers who use their stardust and diplomatic skill to bash heads in the name of conflict resolution.
Former Finnish President Martti Ahtisaari scooped the prize in 2008 for three decades of peacemaking on three continents. Former U.S. President Jimmy Carter secured his 2002 prize for breakthroughs in the Middle East.
Usually the prize goes to former leaders, but the committee broke with that tradition when they made Barack Obama a Nobel laureate in 2009, less than a year into his presidency.
Should the committee look for a current leader, they could consider Angela Merkel. A hot favorite in last year's Nobel speculation for her pledge to welcome as many refugees from warring Syria as necessary, the German chancellor's star has since fallen.
Grassroots activists
Malala Yousafzai electrified the world when she became the youngest ever Nobel winner in 2014. After surviving Taliban bullets in 2012 the Pakistani schoolgirl continued to campaign for children's rights to education.
With her co-winner Kailash Satyarthi, the Indian champion for youth schooling, Malala is the most prominent recent laureate in this category.
Usually the winners are considerably lower key, making predictions tough. However, Denis Mukwege, the Congolese gynecologist who has braved assassins' bullets to treat women brutalized in the country's long running civil war, is a perennial nominee.
Another possibility could be Svetlana Gannushkina, a Russian human rights activist who founded a non-profit group that helps refugees.
