Note: If your Amex MR account is based in the U.S., then AA is not a transfer partner, but BA is, and I think that Amex is running a transfer bonus right now for transfers for BA. If you are going to use BA Avios for the AA flight, don't put the flight on hold at aa.com. Check ba.com to see if the AA flight shows up for Avios redemption; if it does, your can then transfer the necessary number of MR points to get to 25,000 Avios.