If Kuomintang's (KMT) Hung Hsiu-chu is an accidental presidential candidate for her surprise nomination, then the Democratic Progressive Party's (DPP) Tsai Ing-wen, 58, is an accidental politician who wanted to be a "quiet and ordinary person".
"Many years ago, I was someone who liked to hug the wall when I walked. I was an academician who did not like attention from others and was not used to being a focus of society," Dr Tsai wrote in her autobiography published in November 2011, during her campaign for the 2012 presidential election. She lost to incumbent Ma Ying-jeou of the KMT. "However, the vast changes in my life exceeded my own plans and expectations."
The daughter of a car workshop owner who became a successful property developer, Dr Tsai had wanted to study history and archaeology because she would need only to dig into the past and not have to deal with people.
However, her father wanted his youngest child to study law to help with the legal matters of his business. Filial daughter that she was, she took a law degree at National Taiwan University.
She went on to earn a master's at Cornell University in the United States and a doctorate at Britain's London School of Economics.
Upon her return to Taiwan in 1984, she taught at various universities before an opening came up to take part in Taiwan's negotiations for entry into the World Trade Organisation. She went on to become a key negotiator.
Dr Tsai also did research on cross-strait issues at the National Security Council under the government of then President Lee Teng-hui and made policy recommendations. She was said to be one of the masterminds behind Mr Lee's two-states theory in 1999, which angered China so much that semi-official cross-strait exchanges that had begun in 1993 ground to a halt.
She went on to become cross-strait policymaker as chairman of the Cabinet-level Mainland Affairs Council when the independence-leaning DPP's Chen Shui-bian came to power in 2000. She was also vice-premier for a short period during his second term.
But her true turning point from bureaucrat to politician was in 2008, when she became DPP chairman after the party fell from power, discredited by the corruption scandals surrounding Chen.
Dr Tsai took on the heavy responsibility of nursing the ravaged party back to health, after some persuasion from party supporters, for the sake of preserving democracy. She wrote in her book: "In a mature democratic society, if there is no strong opposition party, then democratic politics will most likely regress.
"I will never be able to forgive myself if I choose not to do what I know I can."
It was, however, not easy to transform herself into a politician. DPP legislator Hsiao Bi-khim told Time magazine recently: "She used to sort of hide behind me when we went door to door."
Although Dr Tsai lost in the 2010 mayoral election in New Taipei City, to current KMT chairman Eric Chu, and the 2012 presidential polls, the DPP has recovered, winning big in last November's local polls.
Helped by the deep unpopularity of President Ma, mistrust of his China-friendly policies and economic uncertainty, as well as her own popularity, Dr Tsai is the favourite to win next January's election. She has a rating of 54 per cent against Ms Hung's 19.5 per cent.