The role of push-pull design in electronics is well known. In this paper this role is examined in connection with split contact DFB lasers. Two or three contacts combined with push-pull modulation permit the energy to be moved laterally back and forth in the laser without changing, while modulating the output. Links between changes in the stored energy and the dynamic chirp are examined showing that changes in the symmetry of the push-pull current drive allow one to tailor the chirp so as to minimize dispersion for a given structure and fiber. Push-pull operation changes the fundamental resonances that limit speed of modulation in the laser and in particular the classic photon-electron resonance is replaced with a structural dependent resonance. For a given gain in the laser it appears that push-pull operation offers higher modulation bit rates as well as the potential for controlled chirp. The intrinsic equivalent circuit for push-pull operation of a DFB is shown to have three poles and the design compromises for operation at 50 and 100 Gb/s are discussed briefly.