Statistical and systematic treatment issues in top mass combinations

Alongside a thorough analysis of systematic uncertainties to constrain their impact on the measurement, a huge precision gain can also be obtained by a combination of preferably uncorrelated measurements. With ever increasing precision of single experiment top quark mass measurements, this approach becomes more and more promising, because the absolute precision gain of refined techniques in both theory and experiment tends to saturate. This talk elaborates on the measures that have to be taken in order to optimise the gain from combinations.