# The Statistical Approach for MapleStory Coin Shops

So I've been looking at the response to the recent changes regarding the V coin shop and event, and I think that rather than grabbing pitchforks and storming the HQ, we should actually look for a solution.

I think looking into Statistics would help this issue quite a bit. In fact, the way I see it, using Statistics can eliminate these issues. If Coin Shops and their events had a max coin limit per day based on a formula, then no matter what types of items are in the shop, how expensive they are, and how many there are, there would always be a sufficient max coin limit.

Here's my thinking:

First, you take each of the items and plot out how much they are worth. Then you take each one's limit and multiply it by its value (for example, a CSS10% is worth 30 coins, and you can get 3, so it'd be 90). Then you sum all of those up for a total coin count.

Compute the average of this data by dividing this total coin count by the total number of items (which includes how many times they can be obtained). Then compute the standard deviation of the data. Finally, compute the number of days in which the coin shop is open.

Finally, the formula for calculating the max coins per day: ((Mean + Standard Deviation) * (Total Items / Total Days)) * .1

Let's look at the current event:

There are 87 items. The shop is open 55 days (11/30/2016 to 1/24/2017). The items total coin cost is 13875, and dividing by the items, gives a Mean of 289.1. The Standard Deviation is 296.5.

((289.1 + 296.5) * (87 / 55)) * .1 = 93 coins max per day. I'd say 95 to make it more logical for a max.

This means that over 55 days, you would get 5225 coins. This is completely reasonable.

Now let's make a non-existant event and look at what the count would be.

Let's say we have a shop where everything is 30 coins, and each one can only be bought once. Let's say there are 50 items. Clearly, the Mean is 30, and the Standard Deviation is 0. Let's say it takes place over a span of 30 days.

((30 + 0) * (50 / 30)) * .1 = 5 coins per day. Over 30 days, you'd get 150 coins. This means you could buy 1/10th of the items. Seems less reasonable.

This is where the ".1" comes in. Adjusting this to .2 would give you 10 coins per day, so 300 coins total and 1/5 of the items.

The .1 is sort of a ratio number for the shop. At .1, under ideal circumstances, the buyer would be able to buy .1 (or one tenth) of the items. Changing this would allow the buyers to get different percentages of the items in the shop.

In conclusion: A formula like this would cause a far more fair amount of max coins per day for each event. And the "ration number" could be changed to make it so players could get more (or less) of the items from the shop if they maxed out coins each day. So I think the formula I outlined, ((Mean + Standard Deviation) * (Total Items / Total Days)) * .1, is a great formula to use to calculate the max number of coins per day a player can get.