Which figure of speech is exemplified in the phrase "Cleveland won by six runs"?

The phrase "Cleveland won by six runs" exemplifies synecdoche because it uses a part of a larger whole to represent that whole. In this case, "runs" are a specific aspect of the game that refer to the overall performance of the team. The term "runs" signifies the score achieved by the team, which is a critical element of baseball but does not encompass the entirety of the game or the team's victory.

Synecdoche often involves referring to a concept in terms of a related part or a key element, allowing for a concise way to express complex situations, like a game’s outcome. The use of "Cleveland" indicates the whole team, but it is the "runs" scored that directly reflect the success in that particular contest, clearly demonstrating how a smaller element can represent a larger whole.