The Internet Pinball Serial Number Database or IPSND collects serial numbers of pinball machines and publishes a database of these on the Internet. Our goal is to make available a registration of all pinball machines in existence and allow tools for slicing, dicing and visualization of the data.

Games: 6,696  Serials: 68,298  Visitors: 74,153,196  Members: 5,619  Photos: 43,827  Lat/Lng: 37,400  Masks: 68,298(1,019.98%)  Traits: 572  Nudges: 222,342  Backglasses: 1,865
  Most Serials: Twilight Zone(1,305)  Most Submissions: Dennis Braun(6,100)  Most Points: Dennis Braun(45,409)  Highest Quality: The Knight(17.00)  Most Nudges: pinballservice-nl(28,209)

We get lots of questions concerning serial numbers and related topics. Here you will find the most frequently asked questions. If you have a question you do not see here, please email the webmaster.
  1. Where do I find the serial number on my Pinball Machine?
  2. Since my serial number is 1256, was it the 1256th game made?
  3. My serial numbers have been destroyed, how can I find out what the serial number was?
  4. My game has lots of numbers on it, how do I know which one/ones are the serial number?
  5. I cannot clearly read the serial number that is stamped into my game, what do I do?
  6. My electronic game also seems to have serial numbers on the circuit boards, but they do not match the game serial number. Which ones should I register?
  7. Why don't 'game part' serial numbers have an actual game model assciated with them?
  8. There are literally milliions of possible serial numbers, why are you doing this? Are you insane?
  9. Can someone steal my serial number if I post it on the IPSND?
  10. Does a lower serial number make a game more valuable?
  11. Can I edit my submissions?
  12. If there are only X number of members, why do some of my stats show a number higher than that?
  13. My serial number is already submitted, should I submit it again?
  14. Why should I submit the location of my serial number in the Google map?
  15. Can I submit a serial number more than once?
  16. What is 'Nudging'?
  17. These Nudging Rules and Serial Bot Points seem complicated, can you explain them in more details.
  18. I need to submit a serial number for a game that is not yet shown in the database, what do I do?
  19. What do I do if my submission has been 'nudged down'? How do I get my points back?
  20. What beer should I drink when I play pinball or submit serial numbers to the database?
  21. What is 'Coverage'...
  22. What is Linear Coverage?
  23. What is Clustered Coverage?
  1. Where do I find the serial number on my Pinball Machine?

    It depends on which game you have and who made it. There is no hard and fast rule on finding serial numbers unfortunately. Some were stamped into the wood, some applied with stickers, others handwritten on the cabinet in various places. Since there are too many manufacturers and game models to list and track, we have created a section of the site dedicated to helping pinball machine owners find the serial numbers on their games. Please visit the Finding your serial number page for more info. If a tip does not exist for the manufacturer you are looking for, then you may also post your own tip or suggestion.

  2. Since my serial number is 1256, was it the 1256th game made?

    The short answer is 'probably not' since most manufacturers didn't necessarily start their production run with #1. Some manufacturers supposedly started at 1001 but that has also been disproved in recent years. Unfortunately, due to the highly competitive nature of the industry, it was common to skip ahead in serial numbering schemes in order to confuse the issue of how many games were being produced. There were probably many other financial reasons that serial numbers were not sequential as well. Some manufacterers, specifically Williams and Gottlieb, used the same serial number sequence for all their games, during those years, you can see serial numbers such as 653128 which definitely does not mean it was the 653128th game manufactured by that company, but it does generally fall in line with the order of models manufactured. More details about the serial ranges are available on each game's serial number registrations page which you can find by using the Search Page.

  3. My serial numbers have been destroyed, how can I find out what the serial number was?

    Sometimes, distributors or operators stamped out,destroyed or removed the serial numbers from their games to make it impossible to track the origin of the game. In the old days, gaming was very competitive and operators used individual markings that allowed them to secretly identify their games if they were stolen or to disguise them if they were in someone else's territory. In the 1990's, WMS started making distributor regions a part of the electronic serial number of every game but that was easily bypassed with a simple electronic modification. Eventually, the distribution regions of games become meaningless and these tracking numbers were dropped.

  4. My game has lots of numbers on it, how do I know which one/ones are the serial number?

    This can be a tricky task sometimes, look at the Finding your Serial Number page for specific instructions on determining your serial number location and format. Another way to find out what your serial number might be is to use the Search Page to find your exact game and look at the serial numbers that have already been registered, from that, you can see the format and range of serial numbers for that exact game which will help narrow down the choices. In some instances, a game may have multiple serial numbers too. Generally, a manufacturer put the serial number on each part of a game; the body, the backbox and the playfield. Sometimes these peices were interchanged between complete games by distributors that had many of the same model. For this reason, you may register each part seperately in the database as we are trying to track as many serial numbers in existence. If a head is matched with a different body, then make a note in the submissions 'comment' field noting which other serial numbers are associated in the complete game.

  5. I cannot clearly read the serial number that is stamped into my game, what do I do?

    Sometimes a manufacturer stamp is light or weak and the impression just didn't make it very far into the wood. In this case, just do your absolute best to get an accurate serial number. If you can't read the serial, please do not guess as we only want serials that are 100% accurate. As mentioned in other answers on this page, sometimes a serial number may exist in multiple places on a game. use the Finding your Serial Number page to look for tips on locating serial numbers and also look at the existing registrations to find similar numbers. If you can't tell if the first number in your serial number is a 4 or a 9 and you notice that all the serial numbers for that specific game that have already been registered all start with the number 4, then you can be fairly certain that it must be a 4. HOWEVER, if there are only a handful of registrations for your specific game, then there might not be enough to make any assumptions. When in doubt, please do not register the serial number.

  6. My electronic game also seems to have serial numbers on the circuit boards, but they do not match the game serial number. Which ones should I register?

    All of them! As long as you can clearly read them. We are tracking the existence of as many serial numbers that came off the production line. It was common for circuit boards to be swapped out of working games and put into other models of the same manufacturer. The serial numbers on these circuit boards prove that a game exists with that serial but it may not be your particular game. In this case, you should register the serial numbers that are on the main game assemblies such as body, backbox or playfield and for every circuit board, register a 'game part' serial number.

  7. Why don't 'game part' serial numbers have an actual game model assciated with them?

    Game parts may be transferred between games of different models by the same manufacturer and sometime even by different manufacturers. Because of this, just because a circuit board in your Joker Poker pinball machine has a serial number, doesn't mean that serial number was on a Joker Poker when it came off the assembly line. Because of this, we do not track game models associated with game parts. In the long run, we are not sure how the game part information may help us, but we want to track it anyway.

  8. There are literally milliions of possible serial numbers, why are you doing this? Are you insane?

    I don't think Im insane, I just like compiling numbers and Im a programmer so this seemed like an interesting project for me to learn ASP.NET and Javascript. Yes, there are lots of serial numbers but I figure that over the course of 50 years, we will collect an immense number of serial numbers and the data might just be interesting. So please bear with me and give us your serial numbers. :-)

  9. Can someone steal my serial number if I post it on the IPSND?

    Well, I suppose they could somehow say they had a game with your serial number, but what would be the point? Serial numbers for pinball machines really aren't tracked like VIN's or engine codes. One of the advantages of registering your serial number that I see is that there is a record of your game serial if it is ever stolen or destroyed in a fire.

  10. Does a lower serial number make a game more valuable?

    The condition of the game is by far the most influential property of a game. Certain serial numbers that determine 'sample' games might make the game more valuable to certain collectors but it really doesn't effect much else. Sometimes, games produced early in production actually have more electronic and mechanical bugs that have not yet been worked out, therefore, from a playability standpoint, sample and early production games may be missing 'features' that were improved later in production.

  11. Can I edit my submissions?

    Yes! Members have the ability to edit their submissions. Once you register and validate your email address, all existing submissions that used that email address will automatically be bound to your account. When you are logged in, you will be able to see your standings compared to all other members in the status box and when viewing your profile page you can see all your submissions ever recorded. To edit a particular submission just go view the details of that submission and you will have an 'Edit this Submission' button in the upper right of the detail section.

  12. If there are only X number of members, why do some of my stats show a number higher than that?

    Well, the stats actually include all submissions including non-members since it really isn't fair to exclude everyone else. So, in my case even, my average SerialBot score seems to always be falling as new people submit serial numbers with higher scores.

  13. My serial number is already submitted, should I submit it again?

    Yes you should! Especially if you are willing to include a picture of the serial number with your submission. Most serials don't have a photo associated with them and so the number can still be wrong, including a picture will completely prove the serial number actually exists. Plus, with the nudging feature, accurate photos can gain even more SerialBot points while inaccurate or illegible photos can have points taken away.

  14. Why should I submit the location of my serial number in the Google map?

    Well, the idea of that feature is that over the long run, as games are bought and sold (or seen at shows), that we can track the serial number just for fun. I think that it might be interesting to see if you bought a pin and looked on the IPSND and saw all the potential places it had been in the past.

  15. Can I submit a serial number more than once?

    Yes, you may submit a serial number every 90 days if you want, however, you shoud only submit the number if something has changed about the serial. A perfect example is a game that has changed locations, perhaps you have moved, or you sold the game and want to update the location. That is a valid reason because we want to track serials as they move around the world.

  16. What is 'Nudging'?

    Nudging is a way for serials submitted with photos to gain or lose serialbot points. Basically it puts your photo up for scrutiny by our crack squad of nudge-master members. They will look at the photo and determine if the submitted serial number matches the photo, if so, they can 'nudge it up', otherwise, they can 'nudge it down'. Based upon the voting, the submission can either gain 3 points or lose 3 points. Until voting has swayed the points +/- 4 points one way or the other, any member may 'nudge' the photo submission. Once the voting has taken the 'nudge' total past +/- 4 points, the nudging is stopped. If the members nudged the submission up, then the submission is awarded 3 poins. If the members nudged the submission down, then the submission loses 3 points (yes, you can get negative points overall depending on the points gained on other factors). This encourages submitters to take photos that are clear and detailed.

  17. These Nudging Rules and Serial Bot Points seem complicated, can you explain them in more details.

    Take a look at the 'Serialbot' tab of any game summary, there is a detailed breakdown of point values. In addition, if you look at the details of any submission, there is a SerialBot score box that breaks down how the final value of this submisssion was determined.

  18. I need to submit a serial number for a game that is not yet shown in the database, what do I do?

    Our database usese the game ID numbers from the Internet Pinball Database (http://www.ipdb.org) since it is *the* standard for game definitions. We periodically sync with the IPDB to get new games and updates to existing games as far as production and other game properties. If your game is not yet in the IPDB, they will add it soon and then we can sync our database to them and the game will appear. If you can't wait that long, just send us an email and we can manually sync the database that evening (we only sync in the early morning hours so we do not adversely affect the the IPDB in any way).

  19. What do I do if my submission has been 'nudged down'? How do I get my points back?

    The best thing to do is to take a better picture and edit the photo in your existing submission. When you remove or edit a photo in any way, the current nudges are cleared and the submission is thrown back into the active nudging pool so members can again vote on it.

  20. What beer should I drink when I play pinball or submit serial numbers to the database?

    It is a proven fact that drinking any New Belgium Brewing beer (like Fat Tire, Sunshine Wheat, Blue Paddle, Ranger IPA, Shift, or your other favorite flavor from NBB) will help you to type faster and more accurately. It has also shown positive effects on photo quality and may cause other members to appreciate your submission more.

  21. What is 'Coverage'...

    Coverage is a term used on the site to describe how many serial numbers of the total range of produced serial numbers are represented in the database. Often times, for pure production number comparison and calculation, we don't necessarily need all 100% of the serial numbers to know that the serial numbers exist. A simple example is that if we have serial numbers 101,123,156,158,168,175 and 200 for a game that had a production run of 100, then if we interpret these serials 'linearly', then we can assume that we have the first serial number (100) and the highest (190) which mean we can guess that we have 100% of the 100 serial numbers accounted for or covered. This problem is obviously more complex that this example, but read below for more info on how coverage works.

  22. What is Linear Coverage?

    Linear coverage is one approach to mathematically understanding serial number sequences. Linear is 1 of 2 approaches that we use for calculating 'coverage' (see the next FAQ question for an explanation of 'clustered' coverage calculations). The Linear approach is the more simplistic way of interpreting serial number data, it assumes that a serial number sequence for a given game is sequential and contains no gaps or skips in the full serial number range. As long as this is true for a game, then the total production run for a game must be the last serial number minus the first serial number. Pretty simple eh.... well yes it is... however, it generally only works out in rare cases and breaks down for some pretty big time periods for the major pinball manufacturers.

  23. What is Clustered Coverage?

    Clustered coverage is another approach to mathematically understanding serial number sequences. Clustered is 2 of 2 approaches that we use for calculating 'coverage' (see the previous FAQ question for an explanation of 'linear' coverage calculations). In clustered coverage calculation, we assume that a game serial number sequence *will* include gaps and/or skips. This was commonplace for manufacturers that used a single sequence of serial numbers for all their games (Williams, Stern) which put gaps between sample and production games as well as gaps along the production run to to sample games of other models. It also applies for manufacturers like Gottlieb that intentionally skipped serial numbers during production just to throw off the competition from guessing the actual production run of a given game.

    The basis for Clustered coverage is that it assumes that the serial numbers will be in groups together.  There is a magic number called the cluster width (currently 200 OR 5% of the defined production run) the the SerialBot uses to group the serial numbers into their cluster. If a number is within clusterWidth of another then those serials would be in a single cluster. If there is a gap of larger than clusterWidth, then that next serial number would go into the next cluster and the SerialBot would continue along all the serial numbers submitted and group each into a cluster. The SerialBot, then takes each group and subtracts the smallest from the largest to get the 'range' for each group or cluster. It then sums up each range for each cluster to make an educated guess on the production run.

    A great example of where this works well is... Black Hole which has less than 1% of its serial numbers registered, but we have about 70% coverage using a clusterWidth of 438 (5%) of it's know production run.

    As more serials are submitted for each game, the clusters become better defined and the coverage will approach 100% much faster, so keep the submissions coming!