Binary black hole systems and their merger are one of the most promising sources of gravitational radiation which is expected to be detected by experiments like LIGO, GEO600, or LISA. About two years ago it became possible to simulate these systems numerically with high accuracy. Since these simulations require very expensive numerical calculations, it is of advantage to derive analytic approximations describing the merger process from such full numerical calculations.

I will give an overview over some general properties of binary black hole systems and our numerical simulation methods, and I will present recent results on analytic approximations predicting the final state of black hole binary mergers.