Tectonically beheaded valleys represent strain markers that can be used to constrain the geometry and kinematics of dip-slip faults. Quantifying the cumulative deformation they have recorded requires introducing several assumptions that are difficult to test, which limits their practical utility. Here we present a new method which eliminates some of these assumptions by focusing on pairs of beheaded valleys and analyzing them in the chi (horizontal channel coordinate normalized by drainage area) – elevation space. This approach allows tectonic deformation to be retrieved without using any information from the lost upstream catchment, and has therefore the potential of reducing uncertainties associated to the tectonic reconstruction of beheaded valleys. We demonstrate the power of this method by applying it to an outstanding beheaded stream network preserved across the Wadi-al-Akhdar Graben (NW Saudi Arabia). This methodological contribution is expected to revive the use of beheaded valleys by morpho-tectonic studies, and stimulate the exploration of its potential for long-term tectonic reconstructions