It has been about four months since I first wrote about the numbers you have to memorize in order to get an even number of rides on your Metrocard, and specifically my favorite: $19.05 for eight rides. I first started looking at the issue after noticing that I could never seem to zero out my own balance. For a while, as I saw the differing amounts collect on my card, I wondered if it was just me. From there, I actually wrote a mathematical proof to convince myself that you literally can’t zero your balance, no matter how many times you refill your card using preset buttons, and no matter how many times you ride. So it wasn’t just me. It was literally every single rider who used the MTA’s preset buttons.

Since that time, I’ve been gratified during my subway travels to see people all over the city buying $19.05 Metrocards. From tourists who don’t want to leave the city with extra balances, to locals who like to know they are only paying for something that is usable, a subset of people seem to have embraced it.

Shortly after I posted my complaints, the MTA responded saying they would “certainly look at this as part of the process involved in rolling out the next scheduled fare increase.”

And just like the seasons, the inevitable fare increases have arrived once again. The new fare is $2.75 and the new bonus is 11%. So what does that do to our Metrocard buying experience starting on March 22nd? So far, the MTA has not made that clear. There are two possibilities:

1) The MTA might update its software and make the issue go away. There are two main ways they could do this. They could either a) ask how much you want on your card (or how many standard rides you would like) and then charge you the proper pre-bonus amount to get you your desired balance or b) change the preset buttons to give you proper even numbers after adding a bonus. Admittedly, this may be more difficult on vending machines that accept cash because of concerns about dispensing proper change, but it is certainly doable on the credit card vending machines.

2) The MTA might leave things as is, with $9, $19 and $39 preset buttons. If they go that route, it’s time to start memorizing a new set of numbers again New York! And the magic number seems to be $22.30. Just use the “Other Amounts” button, type in $22.30 and you get $24.75 on your card… exactly nine trips.

The table below lays out all the other options. Note that because you can’t purchase amounts that don’t end in a 0 or 5, you can only get truly even numbers with two of the rows below in green. Why is the magic number at nine rides and not eight rides like before? Well you simply can’t get exactly eight rides any more. Because math! But you can get nine or eleven….

Let’s hope that the MTA delivers and you never have to use the table above. Even if the machines are old, we are going to be using them through at least 2022 so we are owed a patch. And if they do come through in the end, it wouldn’t be the first time an agency made a change in response to some math on this blog. But if they don’t make a change, $22.30 might just be the new $19.05. We won’t know for sure until March 22nd.

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Special thanks to Shimon Klayman for spotting a typo in the table that was fixed.