Bava Metzia 97B

Without the actual Gemara in front of me it is hard to write about this from memory. Still I think it is important to bring up the subject at least to remind myself and maybe others.
Tosphot in Bava Metzia brings up that famous phrase that I spilled tons of mega-bites on in my little booklet: "Even without Abyee, we have to say what Abyee said." That is,- that the law of Rav Yehuda in Bava Metzia 97b ברי עדיף (certainty is better) is of Shmuel. [In its own context in Ketuboth that means the law of Rav Yehuda comes from Shmuel. Eventually I settled on the idea that Tosphot means only it is the same law, not that it comes from Shmuel.]
The basic context in this: 
Two people come to court. One says you owe me 200 zuz and the other says I do not know. Rav Yehuda says "Certainty wins"

In Bava Kama פרה שנגח an ox gored a cow that was pregnant and its calf is found next to it. We do not know what happened. Did the calf die from the goring or not? If memory serves me I think the owners of the ox were not there but the owner of the cow was and he says it was because of the goring. Shmuel said המוציא החבירו עליו הראיה One who takes money from another needs proof.
In Ketuboth a woman  was found not be be virgin after she got married. She says she was raped  after Kidushin but before the Chupa so she gets the full ketubah. The husband says it happened before the kidushin. Raban Gamliel says we believe her and Shmuel said the law is like Raban Gamliel.
Abyee said the law of Rav Yehuda comes from Shmuel.

Tosphot says even without Abyee we have to say what Abyee is saying.

Tosphot before that said Shmuel in Bava Kama does not believe the owner of the cow because his certainty is weak. He knows the owner was not there and so is not in a position to deny the events. 

What I wanted to bring up about all this is the Tospot Rid (Isaiah from Trani) in Ketuboth 12b, He says the the events of Ketoboth and Bava Kama are almost identical. The certainty is weak and in both cases there is חזקת הגוף. חזקה מעיקראת חזקת בתולה וחזקת מעוברת
My question here is if the Tosphot Rid helps in any way to understand our Toshot in Bava Metzia 97?He is after all saying you can not learn from the case in Ketuboth because there is something different there. He does not say what is different. But perhaps what he means is that if we ignore all other factors and simply look at the plea of the woman who is certain perhaps that is what Abyee and Tosphot mean. ברי עדיף (certainty is better).
So what might be possible to say is that תוספות  means that even without אביי we look at the fact that ברי עדיף (certainty is better) is the case in כתובות. That is, that ברי עדיף (certainty is better) has some strength as a טענה and that is all that תוספות means here also. That even without אביי we should say the law of רב יהודה is derived from שמואל

What I mean is if we take the תוספות רי''ד into account then we have to say that ברי עדיף over there in כתובות is not because of a חזקה but rather has strength on its own merits. We have to say this because in בבא קמא there is also a חזקה. So there is something about the ברי in כתובות that helps even if we do not know what other factors are involved.

I think what you have to do here is to look at תוספות נדה ב' ע''ב. There on the דף we have a מקווה that is lacking the ארבעים סאה volume. The גמרא uses חזקה דהשתא to push back חזקה מעיקרא but only with  a צירוף of another חזקה. On the page תוספות there says either one could push back the  time למפרע at least to make a doubt. Therefore in  כתובות we believe her even though the חזקה דהשתא pushes back the time frame to before the קידושין. Therefore she is believed only because of ברי עדיף. There are other cases where we do go by חזקה מעיקרא like in בבא מציעא ק' ע''א where the גמרא says let give the calf to מרא קמא but that is because there is no חזקה דהשתא working against it.
Also in בבא קמא the fact of the cow having חזקת מעוברת has against  it a חזקה דהשתא  so it makes sense to say המוציא מחבירו עליו הראיה since there is חזקת ממון  of the נתבע. Therefore , I think that our תוספות in בבא מציעא makes sense if we look at it in the light of תוספות in נדה  That is the law of רב יהודה comes from שמאול even if we do not look at חזקות

אני חושב מה שאתה צריך לעשות כאן הוא להסתכל על תוספות נדה ב' ע''ב. יש  יש לנו מקווה  שחסר הנפח של ארבעים סאה. הגמרא משתמשת עם חזקה דהשתא להדוף חזקה מעיקרא, אבל רק עם צירוף של עוד חזקה. בדף הזה תוספות אומרים אפילו אחת מן החזקות  יכולה להדוף את הזמן למפרע לפחות לעשות ספק. לכן בכתובות אנו מאמינים לה בגלל שחזקה דהשתא דוחפת בחזרה את מסגרת הזמן לפני הקידושין. לכן היא נאמנת רק בגלל ברי עדיף. ישנם מקרים אחרים שבהם אנחנו הולכים על ידי חזקה מעיקרא כמו בבא מציעא ק' ע''א שבו גמרא אומרת בואו לתת העגל למרא קמא אבל זה בגלל שאין חזקה דהשתא פועלת נגדה.גם בבא קמא בעובדה של הפרה יש חזקת מעוברת אבל יש נגדה חזקה דהשתא כך שזה הגיוני לומר המוציא מחבירו עליו הראיה שכן יש חזקת ממון של נתבע. לכן, אני חושב שלנו תוספות שלנו בבבא מציעא צ''ז ע''ב הגיוני אם נסתכל על זה לאור תוספות בנדה. כך שהחוק של רב יהודה מגיע משמאול גם אם אנחנו לא מסתכלים חזקות.