This is not a good thing. Googling around suggests that "Blood Tanistry" is a bowdlerisation by one writer of what was originally termed "Bloody Tanistry".
Blood tanistry is the principle that “the most talented male member of the royal dynasty should inherit the throne, commonly by murder and war”. It is used to describe the practical ramifications of the Turco-Mongol, as well as other Central Asian steppe nomad, principles of inheritance and succession. Because all male members of the royal clan are considered to have equally legitimate claims on power, the ruler is the individual who eliminates competitors and re-subjugates the rest of the state formation. The structure may be determined by bonds of personal loyalty to the ruler, which are considered to be dissolved on the ruler's death.So, there's another problem with North Korea.