>In total the thickness went down from 7 to 6 pixels, which is a 14% decrease, making it 14% more likely to miss it.
Pedantic, but chance of miss is actually less than 14% more likely since the user's click location is not uniformly random over the thickness area, it's biased toward the center (normally distributed).
Pedantic, but chance of miss is actually less than 14% more likely since the user's click location is not uniformly random over the thickness area, it's biased toward the center (normally distributed).