Kesubos 75b - Chezkas Haguf

There are 2 approaches on today's daf (Rav Ashi we will discuss tomorrow) to explain the mishna. The first is that R' Yehoshua and R' Gamliel argue whether the chazaka on the money of the husband is stronger than the chezkas haguf of the father (Reisha is like R"Y and seifa is like R"G). R"Y says chezkas mamon is stronger (so husband wins), but w/o chezkas mamon the chezkas haguf would be stronger than the chezkas p'nuya. R"G holds that the chezkas haguf is stronger than the chezkas mamon (so father wins). Tosafos explains that according to R"Y the chezkas haguf, even though there is a rei'usa against it (the blemish is in front of us), it is still stronger than the chezkas p'nuya. Basically, without a chezkas mamon, both R"Y and R"G agree that the chezkas haguf even with a rei'usa is stronger than a chezkas p'nuya. Why?

Perhaps it is because the entire chezkas p'nuya is dependent on whether or not she has a blemish and that is determined through the chezkas haguf. We can further explain this based on R' Shlomo Zalman (Shmatsa 2:1 note 4) who explains the opinion of Pnei Yehoshua that chezkas haguf is stronger than Rov, because Rov is a statistic whereas chezkas haguf is a clarification that this is the way it is (birur). A Rov is stronger than a standard chazaka such as a chezkas p'nuya since they are both merely statistics and the Rov is a more reliable statistic. But, it is not stronger than a chezkas haguf which is a birur. Therefore, a chezkas haguf which is a birur completely overwhelm es the chezkas p'nuya which is only a statistic. Once the chezkas haguf paskens that she did not have a mum when she got married, there is no reason to follow a statistic style chazaka i.e. chezkas p'nuya.

Rava says that when the mum is discovered prior to nissuin when she is in the father jurisdiction, we say "kan nimtzah kan haya" and assume it was there from before eirusin so that it is a mekach ta'os and husband wins. Although there is a chezkas haguf against the kan nimtza, they cancel each other out and the chezkas mamon paskens in the husbands favor. But, when the mum is discovered after nissuin then we assume it only came now. Even if the husband finds witnesses that she had the mum between the eirusin and nissuin when she was still in the father's reshus, she wins. Tosafos explains the rationale that although she has 2 chazakos (chezkas haguf and ein adam shoseh b'kos...) and he has 2 chazakos (kan nimtzah and ein adam mifayes b'mumin), her chazakos are more powerful since they work independently of each other, whereas for him they must both be true.