In an internal combustion engine braking system which may provide compression release braking and/or exhaust braking, methods and systems are disclosed of controlling the overlap between an exhaust gas recirculation event and an intake valve event to optimize engine braking at various engine operating speeds. Optimization may be achieved by selectively advancing and retarding the opening and closing of an exhaust valve for exhaust gas recirculation. The opening and closing of the exhaust valve may be carried out responsive to the monitored levels of such engine parameters as: exhaust manifold pressure, exhaust manifold temperature, cylinder pressure, and/or cylinder temperature. Various engine parameters may be monitored. Control of exhaust gas recirculation may be responsive thereto, such that a monitored parameter does not exceed a predetermined level.