Remember when seat selection was as easy as, you know, selecting your seat? You made a reservation, were asked if you preferred aisle or window, and generally got to sit where you wanted.

But in the endless cash-grab that is flying in 2018, seat selection has gotten massively complicated. And it’s now a sometimes months-long game of chicken with the airlines to see if you’ll pay more for a halfway decent seat. But the odds of getting a good seat for free improve the longer you wait to pick one. You’ve just got to understand how the game works before you play it.

Seat assignments are a complex matrix that not even the airlines understand.

Much like airfares, seat assignments aren’t an exact formula. Airlines use seat distribution engines, inputting factors like how many passengers are on the flight, how far out the flight is, how busy the flight is historically, and the status level of the booking passenger. Those factors are then used to determine how seats are assigned, how long premium seats are held, and which are marked “unavailable” when you make your reservation.

So say you book a flight from LA to Reno for a big hot weekend of nickel slot fun. You go to select your seat and it shows only middle seats available for no extra charge. Everything else is either marked “unavailable” or carries a seat assignment fee. This probably means you don’t have much status with the airline and have booked at a lower fare class.

Your choices here are take the middle seat and pray you don’t sit behind a seat recliner or skip the seat assignment and roll the dice. Your odds are almost always better if you wait.

Betting the airlines is better than betting casinos.

What the airlines are doing is, not surprisingly, trying to maximize their revenues. They’ll hold desirable seats, marking them “unavailable” in hopes that they can sell them to eager passengers closer to the flight date. The distribution program determines when they become “available.” But the fewer people who pay the seat assignment fee, the better your odds of getting a decent seat without spending extra money — since there’s more inventory to assign.

The airline still has to seat everyone, and if good seats are all that’s left when you finally go up to the gate and say “Excuse me, I don’t have a seat yet,” guess where you are? Smack next to a big red lever and miles of legroom, without paying a dime.

Let’s go back to your flight to the Biggest Little City in the world. Say you declined to pick a seat, then went online a few weeks later to see if better seats were magically “available.” Better seats are available, but they’re aisle seats in the back. Seat 27D sounds good, but you really like to maximize your time at the Silver Legacy buffet and want off the plane as soon as possible. Still, you wait.

During the following weeks, the flight fills up. If those people filling it opted to pay for seat reservations, your odds of getting a good seat go down as fewer prime seats are available. If other passengers also stay without seat assignments, your odds go up.

Let’s put it in terms a devoted Players Club member can understand. The house is betting its good seats that people will pay to reserve them. You’re betting your general comfort that people won’t. Collectively, if we all declined seat assignments, we’d pretty much foil the airlines’ game.

Flight day arrives and you show up to LAX still without a seat assignment. Magically, seat 7E has opened up. It’s near the front, but in the middle. You can press your luck and hope something better is still available at the gate, or just take that 7E at check-in. The longer you wait, the better the payoff. But then there’s a chance that you get a seat worse than the one you’d originally been offered.

Or, your whole gamble could go bust if the flight is oversold and those without seat assignments get bumped. Then again, that can also be hitting the jackpot.

This gamble is by no means a guarantee.

Like with any gamble, there are things to consider when playing seat-selection roulette. If you’re flying during a busy time of year — especially one filled with inexperienced flyers — you might want to pay for a good seat lest they actually do sell out. Same goes if you’re on a popular flight. If you’re traveling with more than one person, the whole thing gets trickier. Though airlines are required by law to seat families with children under 14 together, sometimes they don’t, and this gamble won’t pay off. If you and bae want to hold hands all the way to Reno, waiting for assigned seats together is a tougher bet.

The entire seat-assignment process is a calculated scheme by the airlines to get people to pay for assigned seats. It’s a little bit Press Your Luck, a little bit Let’s Make a Deal — and almost always a gamble. Paying the seat assignment fee early is almost always a sucker bet, but that all depends on how much you value peace of mind. Rest assured, you’ll get a seat even if you wait. But how good that seat is depends on how lucky you feel.