somewhat especially with broadheads...use an offset 4 inch fletch...you will no its offset buy looking at how the vane is glued on the shaft. it will be at a 2-4 degree angle instead of parralell to the edge of the shaft...

another fletch is called helical wich gives even more spin....when looking down the shaft you will notice the vane is not only offset but appears twisted(curved) around the shaft ....i cant comment on blazers...i dont use them...i use 4 inch helical feathers and as big an offset as i can get for hunting...slows the arrow down some but it doesnt matter at 20 yards.

an example of this causing spin, would be a table top fan...when you blow at it the fan blade spins.....because of more resistance on one side of the blade than the other(offset) a strait vane has equal resistance on both sides so it doesnt spin