My Articles


Table Tennis Ratings With Poisson Jumps
September 24, 2023. Ratings Central has been providing table tennis ratings for clubs, organizations, and countries around the world since 2004. The database contains over 110,000 players and 4.9 million matches. The Bayesian rating algorithm (in the same family as the Elo, Glicko, and Glicko-2 algorithms) uses a normal mean-zero random walk to model how a player’s playing strength changes in time. In 2018, our largest user, the Austrian Table Tennis Association, noticed deflation of 30 to 40 points per year for players who had been playing for a decade. Also, rapidly-improving players (typically juniors) were sometimes underrated. Fixing the priors that the Austrian Table Tennis Association had used reduced the deflation to 10 points per year. To fix the remaining problems, I modified the temporal-update model by adding a Poisson jump process with jumps of 200 rating points. I set the probability that a jump occurred so that the mean of the temporal update was +7 rating points a year. The algorithm is implemented by discretizing the probability distributions. In my investigation, I used simulation and scoring rules. However, most helpful were graphs of the rating history of individual players and also scatter plots showing the rating change between a player’s first and last event versus the time between the two events. Ratings Central started using the improved temporal update model in 2019. All historical data was reprocessed using the new model. For future work, I present an algorithm for rating individual doubles players.
Ratings Central: Accurate, Automated, Bayesian Table Tennis Ratings for Clubs, Leagues, Tournaments, and Organizations
NESSIS (New England Symposium on Statistics in Sports), September 24, 2011. Video of My Presentation, Program and Abstracts, Presentations and Videos, Photos.
Ratings Central: Accurate, Automated, Bayesian Table Tennis Ratings for Clubs, Leagues, Tournaments, and Organizations
Joint Statistical Meetings, July 30–August 4, 2011. Session, Abstract.
NÖTTV Interview With David Marcus
June 17, 2010.
New Table-Tennis Rating System
Journal of the Royal Statistical Society: Series D (The Statistician), 2001, vol. 50, part 2, pp. 191-208.


What was the recent Nobel Prize in Physics really about?
Guest post on the Computational Complexity blog, October 30, 2022.
Separates the quantum mechanics sense from the nonsense while being as non-technical as possible
Review of Quantum Sense and Nonsense by Jean Bricmont, May 17, 2020.
eLetter to the Editor on the news article Quantum weirdness confirmed by Adrian Cho (scroll to the bottom of the page to see the eLetter)
News article: Science Magazine, vol. 350, issue 6267, p. 1463, Dec. 18, 2015; article requires subscription to access on website. eLetter published Feb. 19, 2016; eLetter can be accessed on Science Magazine website without subscription.
Letter to the Editor on Bell’s Theorem and the Demise of Local Reality by Stephen McAdam
The American Mathematical Monthly, vol. 111, no. 5, pp. 456–457, May 2004.
Dispensing with the Philosophical Baggage of Traditional Quantum Mechanics
Letter to the Editor, SIAM News, vol. 36, no. 4, p. 6, May 2003.


An investment puzzle and speculation as to why some think it is hard
Guest post on the Computational Complexity blog, April 18, 2021.
Obit for Richard Dudley
Obituary for Richard M. (Dick) Dudley (1938–2020), May 19, 2020.
Mathematical Folk Knowledge
Things that (almost) all mathematicians know, but few non-mathematicians know. August 3, 2019; revised December 10, 2023.
Little-Known Resolutions of Well-Known Paradoxes
Discussion of several well-known paradoxes whose correct resolutions are not well known. The paradoxes discussed are the Liar Paradox, the Prisoner’s Dilemma, Newcomb’s Paradox, Is It Rational to Vote?, and the Unexpected Hanging. September 11, 2016; revised June 27, 2017, May 6, 2018, November 14, 2020.
Prisoner’s Dilemma
Letter to the Editor, Notices of the American Mathematical Society, vol. 51, no. 7, p. 735, August 2004.

Table Tennis

Behind the Scenes at the TOC
What happened at the Tournaments of Champions (TOC), June 8, 1990–June 17, 1990. The TOC consisted of the Fifth World Veterans Championships, the 1990 U.S. Open, and the International Junior Championships. Article written August 21, 1990, and published in the USATT magazine that year.
Does It Matter Who Serves First?
Is there an actual (not psychological) advantage to serving first in table tennis as there is in some sports?
Comparison of 11-Point and 21-Point Match Formats
Which 11-point-game match formats correspond to which 21-point-game match formats?
Giving Byes to Top Seeds Is Unfair
The ITTF rule on how to place byes in a single-elimination event can favor a lower-seeded player over a higher-seeded player.
Fundamental Table Tennis Geometry
A discussion of basic table-tennis footwork.

Books and Articles by Other People

Mathematics and Statistics

Retire Statistical Significance by Valentin Amrhein, Sander Greenland, Blake McShane, Nature, 567, pp. 305–307, March 20, 2019
A Comment in the journal Nature co-signed by 854 scientists from 52 countries, including me.
Understanding Numbers in Elementary School Mathematics, 2011, 978-0-8218-5260-6; Teaching School Mathematics: Pre-Algebra, 2016, 978-1-4704-2720-7; Teaching School Mathematics: Algebra, 2016, 978-1-4704-2721-4; Rational Numbers to Linear Equations, 2020, 978-1-4704-5675-7; Algebra and Geometry, 2020, 978-1-4704-5676-4; Pre-calculus, Calculus, and Beyond, 2020, 978-1-4704-5677-1; by Hung-Hsi Wu, published by American Mathematical Society
Read these books if you have a child learning mathematics in school or wish to understand school-level mathematics yourself. Errata.


Quantum Sense and Nonsense by Jean Bricmont, Springer Cham, 2017, 978-3-319-65270-2
An antidote to the nonsense of the usual explanations of quantum mechanics. Cats cannot be both alive and dead (which was Schrödinger’s point).
Making Sense of Quantum Mechanics by Jean Bricmont, Springer Cham, 2016, 978-3-319-25887-4
Another antidote to the nonsense of the usual explanations of quantum mechanics. More technical than the author’s Quantum Sense and Nonsense. Read them both.


Coding Guidelines: Finding the Art in the Science; What separates good code from great code? by Robert Green and Henry Ledgard, ACM Queue, vol. 9, no. 11, November 2, 2011
An article on how to write great code. I’m mentioned in the Acknowledgments at the end.
Professional Pascal: Essays on the Practice of Programming by Henry F. Ledgard, Addison-Wesley, 1986, 9780201117769
A must-read book on programming (regardless of whether you use Pascal).


Devil to Play by Eric Dexheimer, Westword, July 1, 1999
Denver Tennis Club’s 4.5 men’s team.


Collision Course by T. Christian Miller, Megan Rose, Robert Faturechi, Agnes Chang, Pro Publica, December 20, 2019
When the USS John S. McCain crashed in the Pacific, the Navy blamed the destroyer’s crew for the loss of 10 sailors. The truth is the Navy’s flawed technology set the McCain up for disaster.
When Failure is Not an Option by Robert Pool, Technology Review, July 1, 1997
Some organizations seem to have purged “human error”, operating highly complex and hazardous technological systems essentially without mistakes. How do they do it?


The Nurturing Parent by John S. Dacey, Ph.D., and Alex J. Packer, Ph.D., Child, November 1992, pp. 96, 107–109, 112–113, 216
6 Ways to Make Your Child Happy (and why they work).


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