[runnerunner]

I almost always put a good player on a big flush here. Will he 1/2 pot on the river with a flush? If so, then what does he think that you have? He knows that you aren't betting the river with just a 9 or a low flush, so I would think he would fold all but the A-hi flush and he might fold the A-hi flush some % of the time. Value from the river bet has to come from exactly J9.

If he never check raises without the nuts then I like betting the river to get value from J9, otherwise I would check behind.