I understand that a traditional bow shot with fingers needs some flex in the shaft but on a centershot compound bow shot with a release, what problem will result from a too-stiff arrow? Why does an arrow from a centershot bow with a release need to flex? I figured it was imply a trade off with weight; stiffer means heavier so folks go with as light as possible for speed.

From my own experimenting, going too flexible on spine ruins accuracy but I've seen no perceptible difference going stiffer, as long as I maintain acceptable FOC.

Stripa or other bowmasters, Can you enlighten me?