Odds

From BaseballCardPedia.com

Odds: Inserts and short-printed cards usually have the insertion frequency printed on the packs or boxes, appearing like this: "Rookie Subset cards inserted 1:4." This means that on average, one Rookie Subset card will be found in every fourth pack. You should never, eeeever, take these for granted. There is usually some small type on the pack now that says that the odds are based on the total print run and not on any given box or pack. So if you buy a twenty-four-pack box, and pull seven of these Rookie Subset cards, you have "beaten the odds". At the same time, if you only pull five, then you got "screwed." You might complain, but unless you get none of the cards you have a considerable expectation of pulling, no one will care. If you call the card maker, they just might send you a little something to appease you. Just make sure you hold onto the box and wrappers.