  Why is natural supersymmetry neither detected nor ruled-out to date? To
answer this question we use the Bayesian approach where the emphasis on finding
prior-independent features within broader and minimally biased frames is taken
as the guiding principle. The 20-parameter minimal supersymmetric standard
model (MSSM) fits to subjective naturalness indicate the existence of a
prior-independent upper bound on the pseudoscalar Higgs boson mass $m_A$ as a
function of $\tan \beta$, the ratio of the vacuum expectation values of the
MSSM Higgs doublets. For a 30-parameter MSSM this implies that $m_A \lesssim 3$
TeV and $\tan \beta \lesssim 25$ at 95\% Bayesian confidence. Removing the
contradictory subjectiveness within the electroweak fine-tuning measure leads
to finding the naturalness line, $m_A \sim \frac{1}{\sqrt{2}} \, m_Z \, \tan
\beta,$ that reduces by one the number of MSSM Higgs sector free parameters.

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