The Checker Maven

10-Piece Endgame Database Now Available

Here's an astronomy question for our checker fans:

Q. What's denser than the galactic core and has to do with checkers?
A. Ed Gilbert's 10-piece endgame database.

Completed in just under a year (admittedly somewhat faster than the Milky Way galaxy took to reach its present form), and containing the proverbial billions and billions of endgame positions, Ed Gilbert's 10-piece endgame database is dense, rich, and full of checker content. It's the very first product of its type to become available for home use by serious checker enthusiasts, and it is destined to change and enhance top-level checker play as leading players begin to use it for analysis and study.

The concepts involved seem complex on a nearly cosmological scale, so to bring things down to earth, The Checker Maven interviewed database creator Ed Gilbert by email. Here's what Ed has to say about the database and other topics of interest.

CM: Tell us a little bit about the 10 piece database.

Ed: It's a database which gives the exact win, draw, or loss value of every checkers position having from 2 to 10 pieces with up to 5 pieces on a side. Checker programs have used endgame databases for quite a while. What makes this one somewhat newsworthy is its size and the tremendous increase in playing strength that it gives to Kingsrow. Up until about 2001 the largest endgame database that was available to the public was for 6 pieces. At that time several commercial programs introduced 8 piece databases, and free programs like Cake and Kingsrow soon followed with 8 piece databases computed by Martin Fierz and Jonathan Schaeffer.

The number of checker positions that are possible increases rapidly with the number of pieces on the board, as does the size of these databases and the time it takes to compute them. A 6-piece database can be computed in a couple of hours, and easily fits on a 64mb flash drive. An 8-piece database takes a couple of weeks and occupies about 4GB. It is only within the last few years that anyone has been able to build a 10-piece database. Jonathan Schaeffer was able to complete the first 10-piece database in 2003 using the resources that were available to him as a department head at the University of Alberta. He estimates that it took him 15 computer years to build it. The Kingsrow 10-piece database is the first to be available to the general public.

CM: How long did it take you to develop the database? How did you go about it? What would you estimate you've invested in time and expense?

Ed: I started building it in August, 2004, and finished 11-1/2 months later. Before starting, I spent several months working on the program that would build it and optimizing its performance to run as quickly as possible. I wanted to build the database in one year, and I did not want to buy 15 computers to do it! I also had to work out some technical difficulties in building some of the very largest subdivisions. Schaeffer had available to him a powerful 64-processor Silicon Graphics workstation with 32gb of RAM. I had to work out schemes to build everything on my home PCs with only 2gb. I ended up building and using 4 computers to do most of the database computations. By building them myself I was able to save some money, and also get exactly what I needed, which was computers with lots of RAM and the largest hard drives available, but without any other extras normally purchased with a new PC. I didn't need keyboards, mice, speakers, or displays, since these machines were only used to compute databases 24 hours a day. There is a more detailed account of my building the database at my web site here:

It describes some of the computer science involved, as well as my experiences maintaining the equipment and keeping the whole thing running for a year.

CM: How do you think the database will influence checker play and analysis?

Ed: I think it will help identify some errors in published play, and it will allow many difficult endings that have up to now been left as 'probable loss' or 'probable draw' to be conclusively resolved. Many tournament players like to review their games and see if they missed a win, if their opponent missed a win, or if they lost, identify the exact losing move. The 10pc db is a tremendous help with this type of analysis. There is also a small group of analysts that like to try to find draws in absurdly difficult opening lines. I admit to doing some of this myself, although strictly using the computer, since my own crossboard analytical skills are not very strong. I've been maintaining a specialized 10-piece opening book in which I've accumulated new play in ballots like the Black Hole, Twilight Zone, Gemini, Wilderness, Double Cross, Octopus, etc. This opening book is available on the web here:

CM: Although we know that overall you're won't even come close to making a profit, nonetheless in absolute dollar terms the database is, at $160, a non-trivial investment. What do you think is the market?

Ed: I think the number of people that will purchase this is quite small, due to the declining population of serious checkers players. I will be surprised if the money made from selling 10 piece databases will cover the cost of even one of the computers that I used to build it. This is not a money making business! Selling the database allows me to get it to the people that really want it and can make good use of it. As far as the price goes, I think it's an incredible bargain. If you are serious about playing checkers, there is nothing else that comes close to giving you the information it provides. You cannot obtain one of these anywhere else in the world. If you wanted to build one yourself, assuming you had the skills to do it, you'd have to buy a bunch of computers and run them for a very long time. Then you'd have to figure out how to integrate it into a checkers program, which means you'd have to write your own checkers program...

CM: We understand that the database needs some hefty computing power for effective use. Can you tell us something about that?

Ed: A few years ago this was true, but by today's standards the requirements are no longer "hefty." Basically you need a sufficient amount of RAM to cache portions of the database during a search, and you need enough free hard drive space to store it. That means you need about 2gb of RAM and about 250gb of free disk space. There is a way you can use the database with less; you can read the details at the Kingsrow web site. If you're using an older machine that needs more of these things, it's likely you can add them quite inexpensively. A coworker at the office just bought 2gb of RAM for $75, and 320gb hard drives are selling for around that same amount.

CM: Whenever large leaps are taken in computer checkers, such as represented by your database, there is inevitable discussion of "solving" checkers once and for all. Indeed, a university team is working on that very thing. Do you think checkers will be "solved" and how do you think that might affect human play?

Ed: Apparently Schaeffer is getting close to proving the win/loss/draw value of all of the 3-move ballots. This will be a nice milestone in computer science and the culmination of perhaps 10 years of work by his team. I expect that they will simply confirm what people have already known about the ballots for a long time, and it will have very little if any effect on human play. However there always is a small possibility that they will find a draw in one of the ballots thought to lose. If this occurs then it will be big news for 3-move tournament players, and also for that other group I mentioned that likes to look for draws in absurdly difficult opening lines.

CM: You are a world-class checker programmer and database developer. Can you tell us a little about your background and interests? What do you do as a "day job" and what do you do for fun?

Ed: For about the last 27 years I've been working for what used to be called Hewlett-Packard, until they spun off their electronic instrument business as a separate company a few years ago, and now I work for that company, Agilent Technologies. I work in R&D as an engineer developing new products. I'm married, with 3 daughters, two of whom have finished college, while the youngest just turned 20 and has a couple of years left to go. I do a lot of bicycling on my road bike (on an Italian steel frame that I built into a complete bike about 15 years ago), and I've also been a runner and regular lap swimmer for over 35 years. When I was younger I used to race in running road races and triathlons, and now I keep up these activities simply for the enjoyment and the exercise.

CM: Can you tell our readers how they might decide if they want the database, and how they might obtain it if so?

Ed: If you're serious about the game of checkers, and you want to have the most powerful tool for analyzing positions that is available anywhere, then you want the 10-piece database. All the information that you need to obtain it, including PC requirements and installation instructions, are at the Kingsrow web site:

The Checker Maven thanks database developer Ed Gilbert for granting us this interview, and repeats Ed's statement that if you're a serious checker player, the 10-piece database is a true "must have" product. We're getting our own copy as soon as we possibly can.

Database Creator Ed Gilbert
Photo courtesy of Carol Gilbert

06/16/07 - Category: Programs - Printer friendly version
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