  An accurate theoretical template for the galaxy power spectrum is a key for
the success of ongoing and future spectroscopic surveys. We examine to what
extent the Effective Field Theory of Large Scale Structure is able to provide
such a template and correctly estimate cosmological parameters. To that end, we
initiate a blinded challenge to infer cosmological parameters from the
redshift-space power spectrum of high-resolution mock catalogs mimicking the
BOSS galaxy sample but covering a hundred times larger cumulative volume. This
gigantic simulation volume allows us to separate systematic bias due to
theoretical modeling from the statistical error due to sample variance. The
challenge task was to measure three unknown input parameters used in the
simulation: the Hubble constant, the matter density fraction, and the
clustering amplitude. We present analyses done by two independent teams, who
have fitted the mock simulation data generated by yet another independent
group. This allows us to avoid any confirmation bias by analyzers and pin down
possible tuning of the specific EFT implementations. Both independent teams
have recovered the true values of the input parameters within sub-percent
statistical errors corresponding to the total simulation volume.
