This contribution focuses on recognizing professional teacher knowledge regarding probability, specifically the empirical, weak, and strong law of large numbers. The author utilizes a subject matter analysis, called “didactically oriented reconstruction” (DOR), to identify the necessary knowledge elements for successful teaching. The findings reveal the importance of stabilisation as a unifying idea, and knowledge elements are presented using a knowledge network. The author notes the lack of systematic knowledge requirements for teaching probability, specifically the law of large numbers. Overall, this paper aims to stablish a clear and comprehensive top-down approach to the necessary knowledge for effective math teaching.