Sorted by luck

Why the middle months always win

Plinko is fair to every receipt and terrible to every month.

Each receipt bounces left or right at every peg, more or less at random. To end up in January or December it has to go the same way almost every time, which hardly ever happens. Most receipts take a mix of lefts and rights and land near the middle. That pile-up in the middle is a bell curve, and it is why May, June, July and August keep winning while the months at the edges often get nothing at all.

So a Plinko board puts nearly every receipt in the wrong month. In our test runs, only about 30 of 365 landed in the month they were really from.

How to sort receipts by month (without luck)

1. Sort by the date on the receipt, not the day you found it in your bag. The date is what matches your bank and card statements.
2. Keep one folder or envelope per month. Twelve places, one year. When a month is done, it stays done.
3. Check each month against its statement. Every charge should have a receipt, so missing ones stand out. Chase them while you still remember.
4. Snap them as you go. A photo with the date on it can be filed by month automatically, and it won’t fade. The full routine is in how to keep track of receipts all year.

The IRS generally expects you to keep records that support your return for at least three years after you file, longer in some cases. Here’s how long to keep receipts, rule by rule, and which receipts you actually need.

This is general record-keeping information, not tax advice. Your tax professional can tell you what your situation needs.

How to play Sorted by Luck

• Tap Call it and pick the month you think will get the most receipts, then the one you think will get the fewest.
• 365 receipts, one for every day of the year, drop in date order through ten rows of pegs into twelve month bins. Each one is coloured by the month it’s really from.
• Receipts are counted by the bin they end up in. One that comes to rest on top of a divider is on the line and counts for nobody.
• Call the most, the fewest, or both. Ties count in your favour.
• Watch drops a year of receipts with no call, just to see who wins.

Questions

Is it rigged toward the middle?

No. Every receipt drops from the same spot and bounces at random. The middle wins because there are far more paths that lead there than paths that lead to the edges. That is just how a bell curve works.

Can a month at the edge ever win?

Almost never. In our test runs, January and December usually got zero to five receipts while the middle months got sixty or more. Ties at the top happen more often than you would think.

What is the song?

Flight of the Bumblebee by Nikolai Rimsky-Korsakov (1900), which is in the public domain. It speeds up and climbs in key as the receipts drop.

Does ReceiptNest sort receipts by month?

Yes. Snap a paper receipt or forward an email receipt and ReceiptNest files it under the month on the receipt. Export a PDF or CSV for your accountant at tax time. See how the receipt organizer works.

Are there other games?

Yes: Fade Out, Snap vs Pile, The Pile, Escape the Year, Shoebox Sort, Guess the Charge and Before It Fades. All free, no signup.

Sources and credits

• IRS, How long should I keep records?
• IRS, What kind of records should I keep?
• Music: Flight of the Bumblebee by Nikolai Rimsky-Korsakov, 1900 (public domain). Sounds rendered with the MuseScore General soundfont (MIT license).