Adding extra fields to HABTM table

I'm building a fantasy betting site for myself and a few friends to use.

At the moment I have an options(teams) HABTM events(matches) relationship setup.

I'm trying to add two seperate options per event plus the gambling odds for each option for the specific event, so different events may have different odds for a certain option.

echo $form->input('Option.0', array('type'=>'select', 'options'=>$options));
echo $form->input('Option.1', array('type'=>'select', 'options'=>$options));

That works to add multiple options per event, however how can I add odds to each of these options in the HABTM table?