Advantage Tactic: Tracking Spins and Symbols on a Slot Machine

Before I get started, I wanted to make a shout out to @Doppymister on Twitter.  Not only is he a sharp guy when it comes to various AP tactics and an absolute wiz when it comes to points and miles, he is also a nice guy.  I have been enjoying on-and-off again conversations with him on Twitter for almost a year now.  Our Twitter “anniversary” is April 8th if you want to send a card.  I mention @Doppymister because he suggested that there might be some interest in how I analyze slot machines.  Slot machine analysis tactics will require more than one article, and I will have to give some thought on how to approach the topic, but I thought I’d kick off the topic with an article about tracking spins and symbols. 

I hope the topic of counting spins and symbols is marginally more interesting that another reboot of “must hit” math, which I may or may not do at some point.  I’m just not sure what else I can say about must hits that hasn’t been said a hundred times before.  Maybe aggregating some of the information that is out there might be useful, but I don’t know.


This is not an actual result of my analysis.  My analysis is mine.  I’m simply showing you how to approach the analysis on a machine like this so you can do it yourself if you so choose.

Anyway, back to the point at hand…  Why count spins?  Why count symbols?

-          I count spins in an attempt to understand how much a game is taking from me while I wait for an event to occur.

-          I count symbols in an attempt to understand how likely an event is to occur.

I don’t know if you’ve figured this out about me yet, but nothing makes me happier than quantifying the game I’m playing.  I do not like relying solely on “something some dude said” if there is any meaningful amount of money on the line.

Let’s say you find something like this: 

At almost 40X reset, the top line is of interest to me.  Not because that big of a jackpot means it is +EV, but because it is unusual and I would like to take an educated guess if I have a +EV situation. 

Here is what I did.

-          I sat down at the machine.

-          I started sending texts and tweets to see if anyone knew anything about this machine.

-          I quickly figured out I was on my own.

-          In goes a players card and a $100.

A player’s card is the ideal tool for counting spins.  Most machines display the points earned in real time.  X number of dollars gives 1 slot point.  If you have the point to coin in rate from the players club, you know how many spins you took and your total coin in you ran through the machine. 

The next thing you need is the amount of money you lost playing the game.  If you have the amount of money you fed into the machine and the amount of money you cashed out, you have the total amount of money the machine took from you while playing the game. 

If you take the total loss and divide by the total coin in, you know the hold percent of the main game.  Let’s say its 20%.  Another way of looking at this is the RTP is 80%.  Save these numbers.

Before we get to tracking symbols, two things are worth mentioning…

1)      There are cases where you need to subtract certain events you are targeting, such as a bonus game, from the win / loss totals.  With this machine, I was targeting the top line jackpot and not a bonus game, so I had nothing to deduct from the win / loss totals unless I hit the top jackpot, which I didn’t.

2)      More spins is better.  When par sheets are created, the manufacturer simulates billions of spins.  We don’t have the time or the money for that, so get as many spins as you can…  5K spins is ok, 10K spins is good, 20K is better…  The more spins you take, the closer your data will get to the long term results for the machine.

On to tracking symbols. 

I hate this part…  It’s actually work.  Why someone hasn’t invented a symbol tracking app that integrates into my phone camera, I have no idea.  FYI - I would pay for this app if you have it.

I needed to track the “turbo” symbol to approximate the odds of hitting the top line payout.  I already had total spins from the card exercise, now I need to know how often “Turbo” appeared on each reel during those spins.  I don’t know any other way to do this than to keep a count of how often “turbo” appeared on each wheel.

I use an app called “Thing Counter”.  It is available on the google play store for free.  I have personally never had a problem using my phone to count symbols on a slot machine, but I’ve heard stories that are very different from various parts of the country.  Maybe using a small notebook in your shirt pocket would be better?  I’m sure there are plenty of ways, but I’ll let you figure out what works best for you and your situation.  I’m not a lawyer, and this is not legal advice.  Just don’t lose count…  When a symbol you are tracking lands on reel 1, record a tick in reel 1. 

EDIT: Mickey Crimm responded to me on Twitter that this tally counter is very useful for counting symbols.

Now you know the total spins (T) and how often the symbol appears on Reel 1 (R1), Reel 2 (R2) and Reel 3 (R3).  Here is the formula for probability of three turbos occurring at once.


This assumes the symbol is a scatter.  If it needs to be on a pay line, it’s a little more complex, but I’ll bet you can figure that out from here.  If you can’t and would like me to write about how to figure out pay lines vs scatters, I can do that.  Let me know and I’ll add it to the list.

The next step is to multiply the probability of the event to the payback of the event expressed in the number of bets.  Using the picture above, that’s:

$39,500 top line / $2.50 a spin = 15,800 bets

15,800 bets * (R1/T)*(R2/T)*(R3/T)

I’m going to make up a number again…  Let’s call this 22%

Almost done…

The last thing you need is the meter speed, and this is the easiest part.  You need the meter speed because when you hit the jackpot, it will not be where it is when you walk up to the machine…  It will be a higher value based on how much coin you run though the machine and how fast the meter moves. 

To get the meter speed, just count the number of spins it takes to move the meter one cent then divide.  If 10 spins of 50 cents each ($5 coin in) moves the meter one cent, you have a meter speed of .002. (.01/5=.002)

Now add them all up.

80% RTP on the main game + 22% in the meter + .2% in meter speed = 102.2% game.

Let me say this one more time…


This is not an actual result of my analysis.  My analysis is mine.  I’m simply showing you how to approach the analysis on a machine like this so you can do it yourself if you so choose.

Now that I know I have a positive game, maybe I want to play or maybe I don’t.  The last piece of the puzzle is whether I have enough cash and time to take the jackpot down.

If (R1/T)*(R2/T)*(R3/T) is the probability of the jackpot occurring, then 1 / (R1/T)*(R2/T)*(R3/T) is the frequency of the jackpot occurring…  That is how many spins it should take to win the jackpot on average.  The frequency * the bet level is the amount of money you need to get through 1 cycle. 

The jackpot might come down in 3 spins, or it might come down in 3 cycles.  The more cash you have the better, but I would recommend planning for no less than 3 cycles for most machines. 

Lastly, consider time…  Even if you can spin the machine 100 times a minute, remember to consider the silly bonus games, you could be dealing with a day or more of seat time.  You’ll need a plan for that too.

In the end, I did not play this machine, and the analysis cost a fair amount.  Even though I spent some money figuring out that I didn’t want to play, I spent a lot less than I would have if I would have just started firing away at max bet.  Still, I had to take the shot. I’m a gambler and sometimes I lose.