Tainan's first city council district loses a seat because of population decline, which favors the five sitting members and squeezes out newcomers.

• Eight candidates are running for five seats in the northern district covering Xinying, Yanshui, Liuying, Baihe, Houbi and Dongshan, down from six seats.
• The DPP is running three incumbents on a joint ticket with its mayoral candidate Chen Ting-fei, hoping her ground game lifts all of them.
• The KMT nominated only its top vote-getter, Tsai Yu-hui, and is backing a Taiwan People's Party newcomer, Chen Shih-wei, in the first real blue-white alliance test in the district.
• An independent incumbent who finished second last time still has deep local support and friendly ties to the DPP camp.
• Whether the blue-white deal works hinges on Tsai being willing to share votes, something an endorsement alone cannot force.

Outlook: The incumbents start as favorites, and the alliance's ability to move actual votes north of the Zengwen River will decide who takes the last seat.