I don't understand how this works, I guess? If your screen is 60Hz, you're drawing four frames for every one that ends up getting displayed. You won't even see the other three, right? If you can't see the frames, what difference does what's in them make?

[E] Answered my own question elsewhere: the difference is the "freshness" of the frame. Higher frame rates mean the frame you do end up seeing was produced more recently than the last frame you actually saw

Also, your input gets registered faster (happens earlier) in the game world.