there are 3129 decks total on the deck page, with 20 cards each, which brings us to a total of 62580 cards...the odds of finding a shiny pokemon are 1/8192, so it's roughly the equivalent of finding 7 shiny pokemon. (7.6 if you want to get technical, but you can't catch .6 of a pokemon!)

7 shiny pokemon's worth of bad luck...