ogeray said:each box has a different pattern
you can only do this with sealed cases
No, the pattern is the same, it's just where you start in the pattern.
Knowing this, I can theoretically open a few packs in a box and then be able to pinpoint where all the holo packs are based on the initial packs. If I get lucky and hit the full art on my first one, I'll know exactly where I am in the pattern right away and won't have to bother opening non-holo packs. The minimum required packs to open without hitting a full art is 3 while the maximum required is just 4.