The Birth Middle Name number is the second of the three name-part totals, derived by summing the Pythagorean letter values of the middle name and reducing. Numerologists read it as the most private of the three, the reserve of the self that is seldom spoken and rarely known to others, a hidden resource or, in some readings, a hidden strain, drawn on in circumstances the public first name does not reach. Because many people have no middle name, or several, the number is treated as an optional and supplementary influence rather than a core one.
Where the given name draws on Balliett, Cheiro and Jordan alike, the private, seldom-known middle name is comparatively neglected in the sources: Cheiro's 1926 book worked chiefly from the full birth name as a single unit, and it is Jordan's 1965 systematisation, more than Balliett's original 1908 chart, that is usually credited with treating the middle name as its own separable total worth a reading in its own right. Not every modern numerologist works with three separate name parts: Dan Millman's widely read 1993 book The Life You Were Born to Live builds its entire system around the Life Path number computed from the birth date alone, without any middle-name figure at all, a reminder that the elaborate name-part chart described throughout this family of articles is a particular, Balliett-and-Cheiro-era elaboration rather than a feature of modern numerology as such.