Generally, shingles should be staggered at 6 inches. Here, you can see that the shingles are lined up improperly.

If you suspect your roof has been hit by hail, the first thing to check is soft metals on gutters, vent caps, and other soft metals protruding from your roof surface.

Here, you can see that someone attempted to patch this roof with mismatched shingles. This definitely could draw the attention of prospective buyers.