Penelitian ini ingin menganalisis kekalahan Ratu Ati Marliati pada pilkada Cilegon dan kemenangan Ratu Tatu Chasanah pada pilkada Kabupaten Serang. Padahal kedua petahana dari dua dinasti politik di Kota Cilegon dan Kabupaten Serang memiliki beberapa kesamaan, baik latar belakang keluarga maupun dukungan politik. Hal ini terjadi karena beberapa faktor yang menyebabkan mereka berbeda nasib dalam pilkada serentak pada 2020 di kedua wilayah ini. Penelitian menggunakan teori boundary control Gibson (2012), dan dilengkapi dengan analisis strategi informal dan ilegal dari Buehler (2018) dan permainan tertutup (closed game) dari Behrend. Menggunakan metode kualitatif, penelitian ini memperlihatkan bahwa faktor kekalahan Ratu Ati disebabkan kegagalan dalam menerapkan strategi boundary strengthening, yang kemudian diiringi dengan keberhasilan oposisi menerapkan strategi boundary opening. Faktor-faktor yang menyebabkan kekalahan itu adalah ketiadaan aktor utama, konflik kepentingan elit partai, kontrol politik yang lemah, mesin politik tidak bekerja optimal, tidak ada akses terhadap elit partai di pusat, dan banyaknya kompetitor. Sedangkan faktor kemenangan Tatu Chasanah karena dia berhasil menerapkan boundary strengthening. Hal ini tampak dari besarnya dukungan partai politik, memobilisasi dukungan baik dari birokrasi maupun dari kelompok-kelompok masyarakat, sehingga mampu mengubah arena permainan menjadi tidak kompetitif. Hal ini memperkuat teori dari Gibson mengenai strategi boundary strengthening dan strategi boundary opening di Kota Cilegon dan Kabupaten Serang.

---

This study wants to analyze the defeat of Ratu Ati Marliati in the regional elections in Cilegon and the win of Ratu Tatu Chasanah in the regional elections of the Serang Regency. Even though the two incumbents from these two political dynasties have several things in common, both from family backgrounds and political support. This happened due to several factors that caused them to have different fates in the simultaneous local elections in 2020 in these two regions. The research uses Gibson's boundary control theory (2012) and is complemented by an analysis of informal and illegal strategies from Buehler (2018) and closed games from Behrend. Using a qualitative method, this research shows that Ratu Ati's defeat was caused by the failure to apply the boundary- strengthening strategy, which was followed by the success of the opposition in implementing the boundary-opening strategy. The factors that led to the defeat were the absence of the main actors, the conflict of interests of the party elites, weak political control, the political machine did not work optimally, there was no access to party elites at the center, and there were many competitors. Besides, Tatu Chasanah's winning factor because she succeeded in implementing boundary strengthening. This can be seen from the huge support of political parties, mobilizing support from both the bureaucracy and community groups, to turn the playing field into an uncompetitive one. This strengthens Gibson's theory regarding the boundary strengthening strategy and the boundary opening strategy in Cilegon City and Serang Regency.