User blog comment:Ultimate Law of Kaitlyn/Why I think Crocodile losing to Luffy was a fluke/@comment-3425840-20120610143405

While I do agree in most parts the thing is, this issue in particular is not debated; i.e. the manga itself depicted Luffy and Crocodile's battle in such a way that shows that Luffy only won because of the environmental advantage at that point (like you said, confined space) and some plot armor.

Aside from that, I think the other two people who took the baptism without flinching were Jinbe and Ace (not Daz Bones).

Finally, I do agree that Crocodile is very knowledgeable, however he is very arrogant at the same time. From what has been hinted so far, both Mihawk and Doflamingo are beyond his level of strength (I don't think Whitebeard is even needed to be discussed) yet he approached them in a rather foolish manner. Also by the end of the war, unlike people such as Hancock, Doflamingo, Mihawk and some others, Crocodile was in fact injured (not as badly as Luffy of course but he himself said to Daz Bones that he had healed up which implies that he needed to recover from the wounds).

As for him being more knowledgeable about the his fruit than the Admiral, what you mentioned is speculation. Just because he said that he knows of its details and the Admirals did not say anything does not imply they know less. None of the Admirals were ever caught off guard in the series so far, the only occasions when any of them were injured were when they were fighting notable powerful figures who are haki users.