Question about Screen Tearing

[Zalkarmus]

When I play certain games that I can get over 100fps in, with vsync off, there's next to no screen tearing. Now, if I limit my fps to 60ish screen tearing becomes worse. If I limit my fps and turn on vsync the tearing goes away, but input is laggy. So, what causes the screen tearing to get worse when my fps is around the refresh rate of the monitor?

 

[bystander]

It's just random. You may see it worse as it may be traveling up and down, but without v-sync, screen tearing is random until you go past your refresh rate, then it can get worse.