The normalized differences between the inferred spectrophotometric parallax and the Gaia parallax for individual LAMOST OB stars. Only the results from stars with robust Gaia parallaxes (﹩\varpi /{\sigma }_{\varpi }\gt 10﹩) and decent spectral quality (﹩{\rm{S}}/{\rm{N}}\gt 50﹩) are shown. The histogram in black shows results from stars of all geometric ﹩{M}_{K{\rm{s}}}﹩, while the red one shows only results for stars with geometric ﹩{M}_{K{\rm{s}}}\lt 0﹩. Our method is more effective for finding binaries for the latter. The vertical dashed line delineates the criterion adopted for binary identification.