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: 6,703  Serials: 71,514  Visitors: 84,112,794  Members: 5,850  Photos: 46,876  Lat/Lng: 40,084  Masks: 71,514(1,066.90%)  Traits: 580  Nudges: 237,660  Backglasses: 1,865
  Most Serials: Twilight Zone(1,372)  Most Submissions: Dennis Braun(6,181)  Most Points: Dennis Braun(46,015)  Highest Quality: The Knight(17.00)  Most Nudges: pinballservice-nl(30,669)
Sink or Swim - IPSND/IPDB No. 2163 - May 1935
Backglass Image
Manufacturer: G. M. Laboratories, Inc. (1935-1936)
Players: 1
MPU: None/Unknown
Production Run: Unknown
Game Type: Electro-mechanical (EM)
Submissions: 0 serials registered.
Coverage help:

Coverage is a mathematical interpretation of the serial numbers that have been submitted so far. The term 'coverage' relates to the amount of the production run that has been 'covered' in the given submissions.

There are two coverage methods shown, each has a different approach of calculating an guess on the number of games produced by analysing the currently submitted serial numbers.

Linear: Linear coverage simply looks at the highest serial number and subtracts from it the smallest serial number to estimate the number of games produced. For some games, this works fine because the serial numbers were sequential and without gaps (Early Bally, Early Stern, etc). However, this approach starts to fail quickly for games that serial numbers are part of a bigger numbering scheme (Williams pre 1984, Current Stern) or that intentially had gaps/skips in the numbering sequence(Gottlieb post 1960). If you see a linear coverage number that is higher than the known production run, it is probably not the best way to look at the serial range and you should look at the clustered approach below.

Clustered: Clustered coverage assumes that there are gaps/skips in the serial sequence for a game. It groups the serial numbers together based upon how close they are to the next serial number in the sequence. If they fall within a certain threshold then the SerialBot assumes that there are valid serial numbers between the two. If they are far enough apart, then the SerialBot assumes this is a gap. Once all the gaps and groups are determined, it sums up all the linear ranges in each group. This way, if a sample run of games started at 15,000-15,100 and the production games started at 17,000 onwards, it would assume that the serial numbers between 15,100-17,000 were a gap an are not counted. Using this method, as more serial numbers are submitted the gap analysis will get more accurate.

0 linear / 0 in 0 clusters 50 wide.
Cluster Serial Number SerialBot Submitted By Country Game Part

There are no serials registered for this game. You could be the first!

Submit a new Game Trait

The following traits help

Game Traits are properties for an individual game that you would like to see tracked along with the other information gathered for a serial number submission. Some examples of existing traits are... Joust: Black or Blue bottom Arch, Black Knight: Faceted Inserts or Normal Inserts, Twilight Zone: 3rd Magnet Installed or not.

have been submitted for this game...

Field NameDescriptonSubmitted BySubmit DateSubmitted
There are no traits submitted for this game

Cluster Serial Number Country

This section lists any known game part serials that happen to match this game's serial mask (if defined). What this can tell you is if a game has any orphaned parts that might exist in other machines. This generally applies to CPU/MPU boards, Driver Boards, Display boards etc that are easily moved from game to game. Repair shops and distributors often robbed parts from other 'scrap' games laying around in a pinch if they were not able to fix the original part or of the original part was damaged beyond repair. If serials start showing up in the database as 'game parts', there is potentially a good chance that that game has been parted out completely, which is unfortunate. It is becoming more and more common for people to part out games and sell them on ebay simply because the seller can often make more money that way.... Please do not sacrifice complete games for money!!!

SerialBotSerial NumberTypeSubmitted ByCountryDetails
There are no submitted game part serial numbers for this game

This section lists any known information about how to physically find serial numbers on games created by this manufacturer. For all manufacturer tips, please visit the Serial Tips Page . (Please do not post serial numbers here on this form.)

There are no tips submitted for this manufacturer
Members can submit new tips on how to find serial numbers! Sign up for a free membership here!

This game has the following serial number formats defined in the database. As serial numbers are sumbitted, trends are recognized and defined or information about a serial number format is collected through historical information.

TypeExamplesRegExMaskLowerLimitUpperLimitAutoAssignable
There are no formats yet defined for this game.


The Serial Bot Summary information here gives a detailed explanation of the Serial Bot analysis for this specific game. The theory behind the Serial Bot is this...

Every game has many many serial number submissions, the goal of the IPSND is not to guarantee that *all* information is 100% correct but that over time, the system should automatically devalue inaccurate submissions while increasing the value of correct submissions.

You may click on the SerialBot score of any submission to see how it was calculated.

SerialBot Color Codes:
- Not Validated The serial number submission has not yet been validated by the submitter via email.
- Unknown There is no known information on the serial number format for this game yet. As more submissions are received we can start to make a best guess on the serial number format.
- Good If a serial does not fail any of the tests for a status of Warning or Bad, then it is good.
- Suspect A serial will have a suspect status if the format is technically correct but there is something wrong with the data. Examples might be that the number might be too high or low for the known range of serials for this game.
- Bad If a game has a serial number definition mask defined for it, then a serial may be marked as 'bad' if the number does not validate agains the mask. Masks are created for games by looking at known serial number formats and consist of a regular expression to define the format of a game serial.

SerialBot Scores:
1 Point Awarded if the serial number has a game assigned to it. This autoatically makes submissions with a known game more valuable than submissions without a known game.
1 Point Awarded if the serial number has been 'verified' by the submitter. A submission is 'verifed' if the submitter clicks on the link in the email sent to them for each submission. The basis for this rule is that submissions by people that do not take the time to respond to the email might be entering garbage data and/or giving fake email addresses. However, it is common for 'verification' emails to get stuck in spam filters etc, so, members may have 'verification' emails re-sent at any time.
1 Point Awarded if the submitted serial number matches one of the predefined serial number masks for this game.
1 Point Awarded if the serial number was marked as 'Physically Viewed' during the submission process. This is an interesting distinction as there are many times that serial numbers are submitted off owners lists, Ebay auction, etc. While these serial numbers are valuable, they may also be innacurate. In comparison, Physically Viewed serial number submissions are numbers that the submitter has actually been in front of the machine reading the number and then submitting it. Since it is more likely to get a good visual from a physically viewed machine, this gains an extra point.
1 Point If a photo is uploaded with the serial number submission. The submission automatically gains an additional point. Be aware however that this opens the submission up to 'Nudges' by members where even more points can be added or subtracted based upon the quality and accuracy of the photo.
-3 to +3 Points Members can 'Nudge' every sumitted photo once and give it an extra boost of 1 point or take away 1 point depending if the photo matches the submitted serial number. While any number of members may nudge a serial, the nudging can only affect the score by +/- 3 points in either direction.

The following map shows the locations of all serial numbers that were submitted with a geolocation...