  The Principle of Maximum Conformality (PMC) provides scale-fixed perturbative
QCD predictions which are independent of the choice of the renormalization
scheme, as well as the choice of the initial renormalization scale. In this
article, we will test the PMC by comparing its predictions for the strong
coupling \alpha^s_{g_1}(Q), defined from the Bjorken sum rule, with predictions
using conventional pQCD scale-setting. The two results are found to be
compatible with each other and with the available experimental data. However,
the PMC provides a significantly more precise determination, although its
domain of applicability (Q \gtrsim 1.5 GeV) does not extend to as small values
of momentum transfer as that of a conventional pQCD analysis (Q \gtrsim 1 GeV).
We suggest that the PMC range of applicability could be improved by a modified
intermediate scheme choice or using a single effective PMC scale.
