This clearly demonstrates the intuition behind randomized compiling (RC): coherent errors can build up as a function of circuit depth, resulting in errors in the bare quantum state (blue vector) compared to the ideal quantum state (black vector). By generating 20 different RC circuits (orange points) at each circuit depth, and combining their results (orange vector), we can see that the RC result is much more aligned with the ideal state. The consequence of tailoring coherent errors into stochastic Pauli errors can be seen in the average reduction of the length of the RC vector compared to both the ideal state and the bare state. Since the RC vector is almost perfectly aligned with the ideal state in each case, the fidelity of the RC state can be approximated by the length of the RC Bloch vector.