  We use MasterCode to perform a frequentist analysis of the constraints on a
phenomenological MSSM model with 11 parameters, the pMSSM11, including
constraints from ~ 36/fb of LHC data at 13 TeV and PICO, XENON1T and PandaX-II
searches for dark matter scattering, as well as previous accelerator and
astrophysical measurements, presenting fits both with and without the
$(g-2)_{\mu}$ constraint. The pMSSM11 is specified by the following parameters:
3 gaugino masses $M_{1,2,3}$, a common mass for the first-and second-generation
squarks $m_{\tilde{q}}$ and a distinct third-generation squark mass
$m_{\tilde{q}_3}$, a common mass for the first-and second-generation sleptons
$m_{\tilde l}$ and a distinct third-generation slepton mass $m_{\tilde \tau}$,
a common trilinear mixing parameter $A$, the Higgs mixing parameter $\mu$, the
pseudoscalar Higgs mass $M_A$ and $\tan\beta$. In the fit including
$(g-2)_{\mu}$, a Bino-like $\tilde\chi^0_1$ is preferred, whereas a
Higgsino-like $\tilde \chi^0_1$ is favoured when the $(g-2)_{\mu}$ constraint
is dropped. We identify the mechanisms that operate in different regions of the
pMSSM11 parameter space to bring the relic density of the lightest neutralino,
$\tilde\chi^0_1$, into the range indicated by cosmological data. In the fit
including $(g-2)_{\mu}$, coannihilations with $\tilde \chi^0_2$ and the
Wino-like $\tilde\chi^{\pm}_1$ or with nearly-degenerate first- and
second-generation sleptons are favoured, whereas coannihilations with the
$\tilde \chi^0_2$ and the Higgsino-like $\tilde\chi^{\pm}_1$ or with first- and
second-generation squarks may be important when the $(g-2)_{\mu}$ constraint is
dropped. Prospects remain for discovering strongly-interacting sparticles at
the LHC as well as for discovering electroweakly-interacting sparticles at a
future linear $e^+ e^-$ collider such as the ILC or CLIC.
