In this paper, we try to measure the semi-strong efficiency of the sports betting market. In particular, we aim to understand whether the efficiency of the market is realized in the case of fixed odds provided by bookmakers on the four major European football championships. By examining the trends of odds in the event of some major change in expectations about the teams’ results, i.e. when a team’s coach is replaced, we attempt to verify the argument that a profitable betting strategy for the bettor is likely possible. In this case, the market that we are taking into account will be inefficient