public CardList getShopCards(int numberWins) {
        CardList list = new CardList();

        int numberRares = 1 + numberWins / 15;
        if (numberRares > 10)
            numberRares = 10;

        for (int i = 0; i < numberRares; i++)
            list.add(getRandomCard(rareList));

        int numberUncommons = 3 + numberWins / 10;
        if (numberUncommons > 20)
            numberUncommons = 20;

        for (int i = 0; i < numberUncommons; i++)
            list.add(getRandomCard(uncommonList));

        int numberCommons = 5 + numberWins / 5;
        if (numberCommons > 35)
            numberCommons = 35;

        for (int i = 0; i < numberCommons; i++)
            list.add(getRandomCard(commonList));

        return list;
    }