Bitterblossom provides exactly that, ensuring that your deck is always running in the optimum conditions
Play Boosters cost 57, contain 14 cards with 14 rares, and are designed for Limited formats and casual collecting
Where the binomial distribution tells us the probability of getting a specific number of successes with replacement (i.e., equivalent with shuffling your deck, revealing the top card, noting whether its a land or not, then shuffling again and repeating), the hypergeometric distribution takes into account that card draws are, in fact, not independent (i.e., telling us the probability of getting a specific number of successes without replacement, where cards arent reinserted into the deck after being counted as a success or not)
Why Its Rare : Its extremely limited number and its link to a rare event have made it one of the most valuable Pokmon cards
This should hopefully help bulk out and refine your deck, with a few more powerful cards that arent to be scoffed at