This past weekend at a 3D reminded me of this; my pin, my yards, your pin, your yards.
I have my bow/sight set to hit dead on for the distance. If I think 30 yards, that's what I set my sight for.
So, I guesstimated this target for 32 yards and dialed in 32 yards. My arrow went where it was supposed to - luckily the lower 12 ring. My sidekick though thought 35 yards and his arrow went in right beside mine. When we discussed the yards after he gave that I was lucky my bow shoots so fast because that target was 35 yards - giving I would have shot a low 8 or even a lower 5.
Our other sidekick had a range finder and went back any ranged it, 31 to 32 yards, depending where he stood at the stake.
Now, my sidekick who shot for 35 yards wasn't really wrong for his set up. He has a dial-O-matic moveable sight frame (turns dial to the yardage), short length sight bar, has a .030" diameter pin, no magnification, and "logs" for arrows. His .030" pin covers a bit more of the target.
My set up consists of a moveable sight frame set to the length of 8", .019" diameter pin (covers less of the target), 4X lens (gives my old eyes a better look see), and arrows of FITA legal, .355" diameter.
My sidekick has his bow set for him and I have mine set for me - Okay, we see things differently. He shoots my bow and my arrow falls 6" low, well give less for closer and more for longer.
So if you and the person you shoot with have a disagreement in yards, consider the above.