This paper investigates a simple analytical approach that yields the optimal switching thresholds for multibranch switched diversity systems. It also presents a performance optimization based on these optimal thresholds. For multi-branch switched diversity systems, the optimal fixed switching threshold is not only a function of the average channel SNR but also a function of the number of diversity branches. Conventional multi-branch switched diversity systems use a single fixed switching threshold, where computing this optimal threshold is not a simple task when the number of diversity branches is high. We propose a novel multibranch switched diversity system that is based on a set of adaptive switching thresholds instead of a single fixed switching threshold, where a different switching threshold is used every switching. Thanks to the fact that each switching threshold in the set depends only on the remaining diversity branches, the proposed system allows a simple optimization for these switching thresholds. Furthermore, numerical and simulation results show that the proposed adaptive switched diversity system outperforms the conventional system.