Ask the Slot Expert: Are extra bets on slots worth making?

Question: If the RNG determines at the nanosecond I spin if I win or lose, then it seems I should only play one line at a time. If I'm playing a dollar machine with five lines, then did I just waste $4 automatically?

If it is either going to win or lose, wouldn't one line be sufficient?

Answer: Your statements illustrate why I object to the way that some slot writers try to simplify the way slots work. By leaving out some intermediate steps, they give some of their readers a mistaken impression of how the machines work. It's like the disclaimer you see on many cell phone ads: Sequences have been shortened.

The RNG doesn't really determine whether you win or lose. The RNG just generates a stream of numbers. The program running the slot machine uses the numbers generated by the RNG to determine whether you win or lose by using those numbers to determine where the reels will stop. The same sequence of numbers may lead to a losing spin on one game and hitting the Megabucks on another.

If the same set of numbers leads to different results on different games, can we really say your fate is determined by the RNG? No. The RNG is part of the process, but it doesn't solely determine your fate. Mathematically speaking, it's necessary but not sufficient.

My current favorite analogy for the RNG is the electricity entering your home. Electricity allows you to do many interesting things, like lighting your home, reheating leftovers in a microwave, and streaming the latest season of Stranger Things on Netflix, but there's no utility in the flow of electrons itself.

You use the same electricity to power incandescent, fluorescent, halogen and LED bulbs. Slot machines likewise use the same RNG function to help the program running the machine determine the results on Double Diamond, Megabucks, Wheel of Fortune and The Hangover.

So, rather than determining whether you win or lose, I think it's more correct to say that the RNG determines where the reels will stop. The symbols on the paylines then determine whether you win or lose.

Turning to your question, I think what you're thinking is that the RNG gives a win/loss decision, and then the programming somehow figures out what line or lines will be winners. In this scenario, there's no advantage to playing multiple lines because the RNG has determined whether you will win or lose on the spin.

As we saw above, that's not the way a slot machine works. The output from the RNG determines where the reels will stop. The program then looks at the symbols on all of the paylines played to determine whether there is a winning combination on them and then pays accordingly.

You don't necessarily waste your money when you play more than one credit on a traditional, reel-spinning multi-line machine. Playing extra credits enables extra paylines, so your hit frequency will go up. In addition, if there is a bonus on one or more combinations for playing the extra coins, your long-term payback will go up — but rarely enough to offset the extra risk from playing the extra coins.

Mathematically speaking, you usually have the lowest expected loss by playing just one line. Most people play full coin on multi-line machines, though, so they can get paid on every payline.

Question: A lot of video slots let you play extra credits and get a chance for some kind of bonus. I was wondering if playing the extra credits was a good play or does it just take more money from you?

Answer: There are many machines on which playing extra credits makes you eligible for an extra gimmick. The extra bet required can be as low as one credit and as high as doubling your bet. I was just playing the Simpsons slot machine last night and that machine gives you the option to bet extra credits to make the bonuses more likely.

Even video poker is not immune to having extra bets that enable a gimmick. You might have to bet an extra credit to enable a bonus on quads or a few extra credits to enable a wheel-spinning bonus on certain hands. If I remember correctly, you have to double your bet to enable the Dream Card feature on that machine.

Whether betting enough to get these extra features just takes more money from the player depends on the math. On a slot, we can't tell how much the extra features are worth, so we can't tell whether it's worthwhile betting extra to be eligible for them.

We can calculate the value of some video poker gimmicks, however. Jean Scott's The Frugal Video Poker Scouting Guide gives the long-term payback for some paytables when they're available with Multi-Strike or Super Times Pay. If the long-term payback with the gimmick enabled plus the cash back you earn is more than 100%, then it's worth it to make the extra bet. If the total is less than 100%, then you'll probably just lose more when making the extra bet because your expected loss (payback times bet) is higher than if you didn't bet the extra credits.

The purpose of these extra bets and gimmicks is to give players greater volatility. On most spins or hands, the gimmick isn't triggered and the extra bet is just money in the shredder. When the gimmick is triggered, however, you have the chance to win more money over and above what you would have won on the play. Your bankroll goes down faster, but the gimmick gives you the opportunity to have your bankroll jump back up again.

I almost always avoid video poker machines with gimmicks unless I'm playing for low stakes and just for fun and to see if I can score a high-paying hand. I usually make the extra bet on slots, however, because there's no way to know how much this extra bet is really costing me and I like to have all ways to win enabled.