Originally Posted by channa

I'm not sure I follow the logic.

First, the chance of an IDB is extremely rare. Much, much lower than a VDB. If they're oversold, they will likely get the volunteers they need.

Second, if the DL flights are after your AA flights, and they're open, why not be the one to VDB and negotiAAte with them that they rebook you on DL as part of the VDB? That way you get the rebooking the way you want with a voucher to boot.