Nuclear dissipation in capture reactions is investigated using backtracing. Combining the analysis procedure with dynamical models, the difficult and long‐standing problem of competition and mixing of quasi‐fission and fusion‐fission is solved for the first time. At low excitation energy a new protocol able to handle low statistics data gives access to the prescission neutron multiplicity in two different systems48Ca +208Pb, Pu. The results are in agreement with a domination of fusion‐fission in the case of256No and an equal mixing of quasi‐fission and fusion‐fission in the case of Z = 114. The nature of the relevant dissipation is determined as one‐body dissipation. © 2004 American Institute of Physics