Phrase "hundred to one says"

Hi guys,

could you please help me with the phrase "hundred to one says"? Of course I tried google, but except of some examples I didn't find direct explanation...

Examples:

a) But a hundred to one says you give the same old lines to me.
b) Hundred to one says AOL missed the boat.
c) I bet you a hundred to one says thats symantec just goes ahead and releases a new version like 12d that fixes most of these existing issues and makes customers pay full price for an upgrade and most if not all of these existing bugs and problems remain unfixed for version 11d.

or my sentence

d) Hundred to one says she had that day marked down
on her calendar.

Please what does that mean? ..I'm guessing...Hundred to one says = I bet?

thanks a lot in advance.

Tomas.