Many years ago, I got into the subject of stiff side with cedar shafts at an area archery shop. they had an old dusty spine tester. I showed them the spine difference at 90 degrees. Their argument was that arrow spines were tested on spinning shafts, so no matter what, the average would still be good. They were a bit surprised to see how the spine tester worked, I do not think that ever used it before that. for those that don't know, the grain goes at 90 degrees to the bow string and if there are flare out grains, the part that is pointing away goes on top. I shoot both left and right hand in the same bows, I mark which way is up on the arrows that have flared grain with four fletch arrows and shoot them nock index in if I need to.