I agree with JeffB. Start with the BT release and switch if you like. A back tension release can be shot on command. Response is generally slower than a trigger release, but you can definitely force one to go off. In fact, many people struggle with a BT release because they fall into the same pattern that they do with other releasess. The mind will generally find a way to "trigger" any release and most have to fight the urge to do so. Many people hunt with a back tension release, so don't let that stop you. By the way, you can use an index finger release with back tension, it's just harder to learn the technique. Once you get it down, it's every bit the surprise release, that a conventional BT release gives. I often wish I could start from the beginning and not have to break all my bad habits.