I came across this fine animation by Will Bowmaker recently and had to grab it, as it demonstrates perfectly the importance of correct arrow spine, especially for recurve shooters. What is “Spine”? Spine when relating to arrows is the stiffness or flexibility of an arrow measured to a standard formula, If the arrow is too stiff it will not flex enough for the fletching to clear the riser, too loose and it will begin the fourth bend cycle before clearing, either way it may impact the riser causing damage to the fletching and leaving telltale marks on the riser of the same colour as the vanes. Also causing serious fishtailing. ( I see this often with low poundage shooters with arrows that are too stiff). You will notice that I don’t call this bending action “the archers paradox” as I believe with a modern recurve riser with the sight window cut past centre, there is no paradox, the arrow is pointing at the target, (usually a little outside which is taken up by the pressure button at the moment of loose) Although the term “Archers Paradox” still applies to the traditional archers who shoot longbows, or any bow that does noti have a past centre sight window. The paradox being that the arrow hits the target whilst not actually pointing at the target at the moment of loose, sometimes pointing considerably off to one side. Which brings us nicely back to the importance of “Spine” Choosing the correct spine is very important, critical for recurve shooters, slightly less so for compound shooters who mostly use a release aid, thus eliminating the initial sideways thrust of a finger shooters release. Those who shoot a compound bow using fingers instead of a release aid (got to admire that) face most of the same problems regarding spine, arrow rest, centreshot and pressure buttons as a recurve shooter. There is a lot more to spine, its selection and effects than this brief and hopefully lucid summary covers, I am willing to go into it in more detail if there is any interest. Let me know.