The Sages, however, say that since the word "condemn" ירשיען is written defectively, without the usual letter vav ירשיעון that one would expect for plural, it means one judge. Therefore, their count is three judges.
The basic argument here is whether the pronounced form of the word (Rabbi Yehudah) or its written form (Sages) is more important. Other arguments hinging on the same "written or pronounced" premise include the number of blood applications of a sacrifice needed for atonement, the number of walls in a sukkah, and the amount of blood from two corpses that creates ritual impurity.
Art: Three Prophets by Jean Changenet