There are a lot of things that can cause you to miss left. Particularly with a long bow, it is important to maintain a little bend in the bow arm. Locking your bow arm can cause you to miss left. Torqueing the string can cause you to miss left. Not getting your dominant eye over the arrow can cause you to miss left. Pressing your face against your string hand at full draw can move your string hand to the right and cause you to miss left. Having an arrow that is too stiff for your bow could cause you to miss left, but this would happen regardless of where you're shooting. There are other things that could cause you to miss left, but you should probably eliminate these things first.