I was learning Bava Kamma 6b and am having trouble understanding the machlokes between R' Yismael and R' Akiva.
One problem I'm having is at the part of the sugya with Rav Idi bar Avin, he said that R' Yishmael is talking about a case where the animal ate a "row amongst the rows", there are heavy-fruit rows and weak rows nearby (because if there was only one type we'd probably assume that the eaten row was of that type) and we don't know which type of row was eaten, so because of a doubt, the damager has to pay as if he damaged a full row.
But the Gemara right afterwards says that this is a case of "one extracting money from his friend, and the burden of proof is on him" -- when someone (the damaged party) wants to take away money from the damager, he has to prove that it was the best row eaten, and if not then he's only entitled to the weakest row. What did the previous part assume, to say that he pays for a full row? It doesn't explain what the actual argument is. What would R' Akiva hold if it was a "row between the rows", he would hold the opposite that he pays the value of a weak one? But R' Akiva only obligates him for the actual value, so would he agree with R' Yishmael that he pays for a full one? But then what would the argument be at that point?
And also the previous section in fact did take into account that "one who takes money from his friend has to pay", since it (a.k.a., Rashi) said that the row is amongst big and small rows, the simple reason for Rashi saying that is probably because if it was only among weak ones, for sure the damaged one has to prove himself that it was a big row before demanding it, so what changed in between the 2 sections of the Gemara?