Sorry if this is the wrong forum, but i want a straight answer. I know this must have something to do with the phisics on how the ball is moved, however it also may have to do more with biology. now for the question, we've all gotten welts when we've played, now how come the center of the hit is always white, surrounded by a red ring? also, if it's not a direct hit (eg side of the wriste) the white "center" goes in the same direction of the ball, making more of a oval center again surrounded by a red ring. what's causes the different colors in skin.