Levin’s theorem

Levin’s theorem states that, in mathematics, under certain technical conditions, the most effective method to predict future states of a system based on past data cannot be better than an estimate derived directly from the data itself. In essence, it highlights a fundamental limit in forecasting: no algorithm can outperform the best possible use of available historical information. This means that, for complex systems, the best predictions are bound by the quality and amount of past data, emphasizing the inherent challenges in accurate long-term forecasting.