Table Of ContentOne
Jump
Ahead
Springer Science-Business Media, LLC
Jonathan
Schaeffer
ne
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ead
Challenging Human
Supremacy inCheckers
, Springer
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To
Steph andRebecca
for theirpatienceandlove throughout
Preface
Why did I write this book? I'm still not sure. After all, I'm a researcher, which
means I think I know how to write technical papers. But writing for a non-
technical audience is something I know nothing about. It took a lot of effort
before I could force myself to sit down to write the first word. Once I did,
however, it washard not tostop! When I started this project,Ididn'tknow that
I had a lot to say and, in some sense, the results show this. The book is much
longer than I even imagined it would be. Worse yet is that there is a lot of
material that I decided not to include. It's a good thing that the publishers
decided to limit how long the book could be! However, after much soul
searching,IthinkInow knowthereasons whyIwrotethisbook.
Firstandforemost, this book tells an interesting story. It's about the life of
acheckers-playing computerprogram, Chinook, from itscreation in 1989to its
retirement in 1996. In reality the story revolves around two people with
differentviews of the program.As thecreator of Chinook, I wanted topush the
program to become the best player in the world, in much the same way that a
fathermightencourage hissontoexcel atsports.The worldcheckers champion,
MarionTinsley,saw the program asa threattohisincredibleplaying record and
his legitimate claim to be the best player ever. The result was a public battle
between man and machine for supremacy at checkers. In fact, it really was a
privatecontestofmanversusman.
A second reason was to alleviate what I perceive to be a void in the
literature. There are many interesting computer"story" books around, detailing
such topics as the history of computing, companies, personalities, and even a
few on technical products. But I don't know of any that go into the intimate
details of creating a computer program; specifically an "intelligent" one. Tracy
Kidder's TheSoul ofa New Machine, recounting the birth of a computer chip,
was the closest model to what I wanted to achieve. In fact, The Soul ofan
IntelligentProgram wasaworkingtitleforthis bookatonetime.
The third reason has to do with the educator in me. I hoped that I could
write a lucid account of the trials and tribulations of developing a complex
computer program. I wanted to educate people on the difficulties of writing
computer software, and give a realistic, understandable explanation of the latest
computing technology.
The finalreason is personal, and this is the one that Ihad to come to grips
with. I feel a lot of dissatisfaction about the way the story ends. By forcing
myself to express my feelings in words, it has given me the chance to
viii OneJumpAhead
contemplate what I've accomplished and, finally, allow me to restore my pride
inthe project.
There was a tremendous temptation to write a book that glorified the
Chinook project, making it sound like a carefully planned, well-thought-out
researcheffort. Ofcourse, this is baloney.InsteadI decided to write abook that
tried to show the reality ofresearch:personality conflicts, money, stupid errors,
bad ideas, obsession,frustration, and the impactonthe family. Afriend ofmine,
on reading an early draft of the book, said, "You come across as a complete
jerk." The early drafts were cruder with more personal "editorial comments"
interspersed that didn't survive to the final edition. I tried to be honest,even to
the point of saying some unflattering things about myself. I think this was
necessary to give readers a flavor ofwhatreally went on. A"sanitized" version
ofthe story wouldn'tbe asinteresting and as informative. Nevertheless, Ihope I
don'tcome across asajerk!
Apologies
The bookpresents many things from my pointofview and, unfortunately, often
does not properly reflect the time and effort put in by other members of the
team. Every one of them workedvery hard and put in long hours. Please accept
my sincereapologiesifIhave failed to acknowledgeyour contributionproperly.
Beforeyou read thisbook
Computerpeople: Don'tlet the checkers-relatedmaterial turn you off.Ignoreit.
Nevertheless, I encourage you to try to understand what's going on in the
checkers diagrams or play through some of the games. You might discover that
you actually understand the principles with minimal effort. Beware though: the
game isaddictive!
Checkers players: Don't dwell on the computer material. Ignore it. Never-
theless, I hope I have explained the concepts at a high enough level that you
won'twant toskip them!
For the record
I had a serious dilemma in writing this book. Do you say checker player, or
checkers player? Logically it made senseto call a playerofcheckers acheckers
player. However, I quickly discovered that the checkers community (or is it
checkercommunity?)preferredthe former. DavidKramerdid some researchon
this issue and wrote:
Afterconsulting Al Lyman, editor of the ACF Bulletin; a linguistat the
UniversityofToronto;theworldauthorityonbilliards,agamewithasimilar
pluralproblem; and numerous dictionaries andencyclopedias, I havecon-
cludedthatinmostcasesitisinfact"checkers"thatistobe preferred.Now,
Preface ix
one moves a "checker" on the "checkerboard", but that's about it for the
singular.However,accordingtoMr.Lyman...theplural [shouldbe]reserved
exclusively for "the game of checkers." I believe that a combination of
linguistic forces has led to checkers players...making the "wrong" choice.
These forces are euphony (it's easier to say "checker player") and what I
would call guild snobbery, the attempt by the practitioners to elevate the
languageoftheirspecialtyabovethatofthemasses....1
So, forbetter orworse,Idecided tostick withthe"correct"usage.
Another departure from the checkers-community standards is in the
representation ofcheckers moves. Inthis book I usedthe algebraic notation that
is popular in the chess world. It is much easier to visualize moves using this
notation than it is using the checkers community's numeric notation. Even
though I've been using numeric notation for sixyears,I still find it awkward to
use. Algebraic notation issimpler and,hopefully, willallow awider audience to
followthecheckers ideas.
The above points mean than some quotations have had minor consistency
editing done to them. For example, checkers moves in the quotations specified
using numeric notation have been changed to their equivalent algebraic
representation.
All monetary amounts have been approximated to their U.S. dollar
equivalents.
Despite numerous proofreads and double-checking of facts, it's inevitable
thatafew mistakes willbefoundinthisbook.Allerrors aremyresponsibility.
Finally
Come visit our World Wide Web site and playa game against Chinook:
http://www.cs.ualberta.cal-chinook. Goodluck!
JonathanSchaeffer
IPrivatecommunication,November22,1996.
Acknowledgments
This book wouldn't have been possible without the important contributions of
manypeople.Iwouldliketoextend mydeepest appreciationto:
• Chinook team members Martin Bryant, Joe Culberson, Brent Knight,
Robert Lake, Paul Lu, Duane Szafron, and Norman Treloar for their
enormouscommitment totheproject;
• MarionTinsleyforbravelyagreeing toplayus;
• DerekOldburyandHerschel Smithfortheirunswerving support;and
• BobBishopforgivingusourfifteen minutes offame.
Other people making important contributions to the development of
Chinook include: Brent Gorda, Jaap van den Herik, Randal Komelson, Patrick
Lee,DavidLevy,SteveSutphen,andKenThompson.Thank you.
Support was received from: Natural Sciences and Engineering Council of
Canada (NSERC), University of Alberta Central Research Fund, Department
of Computing Science at the University of Alberta, Silicon Graphics Inter-
national, the Netherlands Organization for Scientific Research (NWO),
Computer Science Department at the University of Maastricht (formerly the
University of Limburg), Lawrence Livermore National Laboratory (Eugene
Brooks), andIBM.
The open-mindedness ofthecheckers-playingcommunity gave Chinook its
opportunity tocompete againstthebesthuman players.Iwould liketothank the
American Checker Federation, Marion Tinsley, Asa Long, Don Lafferty, and
DerekOldbury.Allofthemcouldhave said"no"toacomputer.
The contents of this book benefited from interactions with Martin Bryant,
David Butler, Gil Dodgen, Eric Jensen, Brent Knight, Don Lafferty, Robert
Lake, Paul Lu, Stephanie Schaeffer, Herschel Smith, Steve Sutphen, Norm
Treloar, and Tom Truscott. Numerous people read the book and offered me
valuable feedback: Martin Bryant, Jordan Devenport, Martin Devenport, Gil
Dodgen, Dap Hartmann, Andreas Junghanns, Brent Knight, Richard Korf, Don
Lafferty, Robert Lake, David Levy, Paul Lu, Aske Plaat, Stephanie Schaeffer,
ManuelaSchone,SteveSutphen, Duane Szafran,Norman Treloar,Jaap vanden
Herik, and Judy Woken. In particular, Robert Lake, Aske Plaat and Stephanie
Schaeffer were brave enough to read the manuscript several times. Eila Smith
xii OneJumpAhead
suggested the title for the book. Robert Lake helped with the diagrams. The
photographs were contributed by Robert Lake, Paul Lu, and Stephanie
Schaeffer.
I would like to acknowledge three valuable sources of information: Mary
Clark, Marion Tinsley's sister, for providing historical background on her
brother; Donna Hussain, Arthur Samuel's daughter, for providing me with
access to unpublished papers by Samuel (including his autobiography, A Boy
From Emporia); and Jim Propp for his excellent article on the 1994 Tinsley-
Chinookmatch(which,regrettably,wasneverpublished).
I would like to thank the people at Springer-Verlag: Martin Gilchrist,
VictoriaEvarretta,andKenDreyhaupt.Inparticular,MartinGilchristmadethis
book a reality. David Kramer provided valuable feedback, rejuvenating my
enthusiasmforthebookjustwhenitwaslagging.
