  Scientists in quantum technology aspire to quantum advantage: a computational
result unattainable with classical computers. Gaussian boson sampling
experiment has been already claimed to achieve this goal. In this setup
squeezed light states interfere in a mid-sized linear optical network, where
multi-photon collisions take place. The exact simulation of the counting
statistics of $n$ threshold detectors is far beyond the possibilities of modern
supercomputers once $n$ exceeds $100$. Here we challenge quantum advantage for
a mid-sized Gaussian boson sampling setup and propose the approximate algorithm
to obtain the probability of any specific measurement outcome. For an 70-mode
device on a laptop, our approximation achieves accuracy competitive with the
experimental one.
