Period-mass distribution of close MS−BD binaries inferred from close WD−BD binaries using population synthesis technique. We have also overplotted the known transiting A-F-G-type MS−BD binaries with precise BD mass measurements (excluding those only having M sin i measured) from the literature (Pont et al. 2006; Johns-Krull et al. 2008; Winn et al. 2008, 2009; Deleuil et al. 2008; Hébrard et al. 2008; Hellier et al. 2009; Triaud et al. 2010, 2013; Borucki et al. 2011; Anderson et al. 2011; Ford et al. 2011; Bouchy et al. 2011a,b; Siverd et al. 2012; Moutou et al. 2013; Díaz et al. 2013, 2014; Parviainen et al. 2014; Ma & Ge 2014; Bonomo et al. 2015; Csizmadia et al. 2015; Nowak et al. 2017; Bayliss et al. 2017; Hodžić et al. 2018; Zhou et al. 2019; von Boetticher et al. 2019; Carmichael et al. 2019, 2020, 2021; Persson et al. 2019; Šubjak et al. 2020; Mireles et al. 2020; Maire et al. 2020; Grieves et al. 2021; Benni et al. 2021; Acton et al. 2021; Stevenson et al. 2023). Progenitor systems are marked with blue triangles based on a α_CE value of 0.3 except for ZTF J0038+2030, where a α_CE value of 0.45 is used. The error bars illustrate the range of initial orbital periods based on all possible α_CE. The gray-shaded area marks the lowest density area in the BDD proposed by previous studies.