Category: Games
Trampoline question
I gave a talk yesterday, and did not have time to get to this question, from Eric S., which we discussed during the dinner hour:
Who could launch themselves higher on a trampoline? LeBron James or Simone Biles?
She is a world class female gymnast, and much lighter (and less strong) than LeBron. The question is assuming that both parties are motivated to win the competition, and have sufficient time to train to achieve their maximum potential in the contest.
Ultimately I settled on Simone as the better answer, mumbling something about small ants being very powerful for their size, and that magnification and extension of muscle spans ends up producing problematic results. The power gain from the extra weight might be more than offset by the “drag” loss on the way up. But I genuinely do not know. Your view?
Addendum: This is an interesting article on animals and elastic springs. And Jason Kottke adds comment, amazing photo too.
Is North Korea withdrawing from the nuclear talks?
No, they are negotiating, read their latest statement, it is full of “ifs.” If you are negotiating, especially in a fraught situation, often you will feel the need to walk away from the talks, or at least threaten to do so. (Of course, many people suggest Obama should have done more of this leading up to the Iran deal.) And Kim doesn’t want to enter the talks with Trump having had an unbroken string of PR successes.
Now, there is a perfectly reasonable argument for being pessimistic about the North Korean nuclear talks, namely that some of the demands of the two sides may prove incompatible. The good news, if you would call it that, is that we are not actually calling for complete denuclearization of North Korea, though nonetheless we may require more than they are willing to cede. Most of all, we want them to start acting like a normal evil government, rather than like a crazy evil government. Maybe that is too hard for Kim to pull off and still feel stable.
Still, the new news isn’t really bad news at all. It is how an evil tyrannical government negotiates. It is also how some non-evil tyrannical governments negotiate as well, not to mention non-evil, non-tyrannical governments too.
Elite competitors live longer, even in chess
The survival rates of GMs at 30 and 60 years since GM title achievement were 87% and 15%, respectively. The life expectancy of GMs at the age of 30 years (which is near the average age when they attained a GM title) was 53.6 ([95% CI]: 47.7–58.5) years, which is significantly greater than the overall weighted mean life expectancy of 45.9 years for the general population. Compared to Eastern Europe, GMs in North America (HR [95% CI]: 0.51 [0.29–0.88]) and Western Europe (HR [95% CI]: 0.53 [0.34–0.83]) had a longer lifespan. The RS analysis showed that both GMs and OMs had a significant survival advantage over the general population, and there was no statistically significant difference in the RS of GMs (RS [95% CI]: 1.14 [1.08–1.20]) compared to OMs: (RS [95% CI]: 1.09 [1.07–1.11]) at 30 years.
Elite chess players live longer than the general population and have a similar survival advantage to elite competitors in physical sports.
That is from An Tran-Duy, David C. Smerdon, and Philip M. Clarke, via a loyal MR reader.
What can we plausibly hope for with North Korea?
That is the topic of my latest Bloomberg column, here is one excerpt:
First: The North Korean regime has never been bureaucratized in the modern sense of that term. While we don’t have comprehensive information, it seems that until recently Kim as leader had not been going abroad, nor had he been receiving many visits from other heads of state. His position and perhaps his mood has been one of extreme isolation, and he is not surrounded by anything resembling the U.S. State Department or even the old-style Soviet bureaucracies that managed foreign policy for the USSR. The rest of his regime is probably poorly informed about the extent of American military superiority, should a conflict come to pass.
By meeting with other foreign leaders, the North Korean regime would be forced to build up its basic processes for dealing with the rest of the world. That in turn creates interest groups and flows of information (some of which invariably leak out). The North Korean populace responds by thinking more about the outside world, making it harder to control by propaganda. In turn the North Korean leadership may decide to continue economic liberalization.
One need not count on an “End of History” story culminating in liberalism and democratization. The more modest hope would be for the North Korean leadership to become more decentralized, more bureaucratic, better informed and harder to marshal behind crazy military measures.
The unspoken goal of engagement would be to encourage North Korea to evolve into a more banal and more predictable form. That is the natural flow of most bureaucratic organizations, so in this regard American negotiators actually have time on their side. The North Koreans are going to change a lot more than the U.S. is likely to.
And the concluding sentence:
Think of any diplomatic talks with North Korea as a big act of theater — designed not to fool him, but to teach him that theater itself can be fun.
Do read the whole thing.
The Middle East and Syria right now
That is the topic of my latest Bloomberg column, here is one excerpt:
Some historical events are relatively easy to model with game theory: the Cuban Missile crisis, many of the Cold War proxy wars, the crisis over North Korean nuclear weapons. In those conflicts, the number of relevant parties is small and each typically has some degree of internal cohesion.
To find a situation comparable to the Middle East today, with so many involved countries, and so many interrelationships between internal and external political issues, one has to go back to the First World War, not an entirely comforting thought.
The situation right before that war had many distinct yet related moving parts, including the dissolution of the Ottoman Empire, the imperialist scramble for colonies, the prior Balkan Wars, a rising Germany seeking parity or superiority with Great Britain, an unstable alliance system, an unworkable Austro-Hungarian Empire, and the complex internal politics of Russia, which eventually led to the Bolshevik Revolution.
What do we learn from the history of that time? Well, even if the chance of war was high by early 1914, it was far from obvious that the Central Powers attack on France, Belgium and Russia would be set off by a political assassination in the Balkans.
Nonetheless, in sufficiently complex situations, chain reactions can cause small events to cascade into big changes. In World War I, one goal behind the assassination of Archduke Franz Ferdinand was to break off parts of the Austro-Hungarian Empire into a new Yugoslavia. The empire responded by making some demands on Serbia, which were not heeded, a declaration of war followed, and the alliance system activated broader conflicts across Europe.
If you don’t quite follow how a single assassination, which was not even seen as so important the day it occurred, triggered the death of so many millions, and the destruction of so much of Europe, that is exactly the point. When there is no clear way for observers to model the situation, a single bad event can take on a very large significance and for reasons that are not entirely explicable.
Do read the whole thing.
How might game theory shed light on Trump talking to Kim?
That is the topic of my latest Bloomberg column, they chose a nice photo. Here is an excerpt:
If North Korea and the U.S. simply talk, and nothing comes of it, that raises the status of Kim Jong Un, who then would keep improving his missiles anyway. So if the U.S. goes ahead with the talks, you might rationally infer that the risk of war has gone up. Furthermore, there is the risk that Trump or Kim could feel humiliated by a summit that yielded nothing, again raising the chance of war or miscalculation leading to disaster.
In chess there is a concept known as “zugzwang,” or “compulsion to move.” It’s used to describe the position of a player with no good options who would prefer to do nothing at all. That’s not a possibility in chess, so the unfortunate player faces a situation in which all roads involve a deterioration of his position.
There is much more at the link, only one scenario being even somewhat optimistic.
My visit to the World Chess Hall of Fame
A significant part of a St. Louis block is devoted to the world of chess. There is the Hall of Fame, the St. Louis Chess Club, and also a chess-themed restaurant, Kingside Diner, with a King on the men’s room door and a Queen on the women’s room. The facilities are world class and very welcoming for the visitor; I am honored to have been given a personal tour (and to have eaten fish and chips there).
If you see a Slavic-looking face walking down this street, you simply assume it is a chess player. In general, I am very interested in the idea of creating extreme mini-universes, a’la Robert Nozick’s concept of utopia. This is what the chess utopia looks like, and it is in St. Louis. In this world, rating matters more than race or gender or age.
Many of America’s best chess players now live in or near St. Louis, and the two best college teams — Webster and SLU — are both in or near St. Louis.
One lesson is the power of philanthropy in an otherwise under-supported domain. I am instead used to seeing donations in “crowded” areas, such as economics or politics. Rex Sinquefield, a former finance economist, and the developer of index investing, has been the major force behind the rise of St. Louis in chess. The game is now played in more than one hundred of the local schools.
The strangest moment for me was reading through the plaques in the Hall. I had known many of those individuals during the ages 13-16, but for the most part have not had contact with them since, or heard word of them. All at once, I learned when each had died, and which of the few remained alive.
The return of Nigeria’s kidnapped girls
Joe Parkinson and Drew Hinshaw at the WSJ follow up on what was a super dramatic story that turned into a neglected and under-reported tale. What is life like for the Boko Harum kidnap victims after their liberation?
The women had acclimated to the forest camps where Boko Haram insurgents threatened them at gunpoint to either convert to Islam and marry a fighter or be a slave.
About half chose slavery, which cost them access to food and shelter.
Here is another bit:
Psychologists who specialize in kidnap victims say they are unsure about the best way to simultaneously treat and educate such a large group of women—ages 18 to 27—after years of collective captivity and abuse.
The spelling bee contests, one healing piece of the curriculum, arrived as something of a surprise. It was the Chibok girls who came up with the idea.
And:
One night, plopped on couches, they watched “Akeelah and the Bee,” a movie about an 11-year-old African-American girl in Los Angeles who finds her confidence after her father’s death by winning the Scripps National Spelling Bee.
The students watched the movie again and again over bowls of popcorn. They went to their teachers with a demand: They wanted to hold their own spelling bees. The teachers agreed.
The young women began memorizing vocabulary lists and testing each others’ lexicographic skills. Their wordplay escalated into late-night spelling battles. “It was unbelievably competitive,” Mr. Braggs said.
Spelling employs a skill many of the women honed while captive: mnemonic memory. Some spent much of their time memorizing lengthy prayers and hymns. Others composed diary entries in their heads—their thoughts, injustices they suffered—they would later log in journals they kept hidden. In secret, they retold the story of Job, the biblical figure who was punished in a test of his faith.
By the way, 112 girls remain missing and 13 are presumed dead.
The culture that is San Francisco solve for the equilibrium
A man threw his body onto a self-driving car — a GM Cruise AV — causing a car vs. pedestrian collision at the 16th and Valencia intersection earlier this month, the DMV reported Wednesday.
Operating in “autonomous mode,” the Cruise AV was stopped at a green light, facing northbound on Valencia, waiting to make a right turn onto 16th Street as pedestrians crossed.
Suddenly, a man ran across Valencia Street against the “do not walk” sign, shouting, and struck the left side of the car’s rear bumper and hatch with his entire body. This is all according to a report the self-driving car manufacturer must file with the DMV in the event of a collision.
The man sustained no injuries, but the car did. It suffered “some damage to its right rear light,” according to the report.
Here is the full story.
The great Ken Regan on AlphaZero
A must-read for anyone who has been following this issue, Ken considers how close to God AlphaZero actually came:
We must pause to reflect on how clarifying it is that this single heuristic suffices to master complex games—games that also represent a concrete face of asymptotic complexity insofar as their size n-by-ngeneralizations are polynomial-space hard…
It may be that we can heuristically solve some NP-type problems better by infusing an adversary—to make a PSPACE-type problem that hits back—and running AlphaZero.
That sort of thing. And don’t neglect the comments.
The Age of the Centaur is *Over* Skynet Goes Live
“Mastering Chess and Shogi by Self-Play with a General Reinforcement Learning Algorithm”
The game of chess is the most widely-studied domain in the history of artificial intelligence. The strongest programs are based on a combination of sophisticated search techniques, domain-specific adaptations, and handcrafted evaluation functions that have been refined by human experts over several decades. In contrast, the AlphaGo Zero program recently achieved superhuman performance in the game of Go, by tabula rasa reinforcement learning from games of self-play. In this paper, we generalise this approach into a single AlphaZero algorithm that can achieve, tabula rasa, superhuman performance in many challenging domains. Starting from random play, and given no domain knowledge except the game rules, AlphaZero achieved within 24 hours a superhuman level of play in the games of chess and shogi (Japanese chess) as well as Go, and convincingly defeated a world-champion program in each case.
In other words, the human now adds absolutely nothing to man-machine chess-playing teams. That’s in addition to the surprising power of this approach in solving problems.
Here is the link, via Trey Kollmer, who writes “Stockfish Dethroned.” Here is coverage from Wired. Via Justin Barclay, here is commentary from the chess world, including some of the (very impressive) games. And it seems to prefer 1.d4 and 1.c4, loves the Queen’s Gambit, rejected the French Defense, never liked the King’s Indian, grew disillusioned with the Ruy Lopez, and surprisingly never fell in love with the Sicilian Defense. By the way the program reinvented most of chess opening theory by playing against itself for less than a day. Having the white pieces matters more than we thought from previous computer vs. computer contests. Here is the best chess commentary I have seen, excerpt:
If Karpov had been a chess engine, he might have been called AlphaZero. There is a relentless positional boa constrictor approach that is simply unheard of. Modern chess engines are focused on activity, and have special safeguards to avoid blocked positions as they have no understanding of them and often find themselves in a dead end before they realize it. AlphaZero has no such prejudices or issues, and seems to thrive on snuffing out the opponent’s play. It is singularly impressive, and what is astonishing is how it is able to also find tactics that the engines seem blind to.
Did you know that the older Stockfish program considered 900 times more positions, but the greater “thinking depth” of the new innovation was decisive nonetheless. I will never forget how stunned I was to learn of this breakthrough.
Finally, I’ve long said that Google’s final fate will be to evolve into a hedge fund.
Kim Jong Un is rational in a very long-term game
That is the thesis of my latest Bloomberg column, note that Kim is only 33 and could be around for another fifty years or so he hopes. Peaceful exile probably is not an option! So how does one hold onto power and avoid those anti-aircraft guns? Here are some excerpts:
It is very difficult to predict the world a half-century out. Fifty years ago, China was just coming out of the Cultural Revolution, and Japan’s rise was not yet so evident. North Korea was possibly still richer than the South, which in 1960 was one of the poorest countries in the world. It’s unlikely anyone had a reasonable inkling of where things would stand today.
So if you are a dictator planning for long-term survival under a wide range of possible outcomes, what might you do? You don’t know who your enemies and your friends will be over those 50 years, so you will choose a porcupine-like strategy and appear prickly to everyone.
We Americans tend to think of Kim as an irritant to our plans, but his natural enemy in the long run is China. It is easier for North Korea to threaten Chinese cities with weapons, and its nuclear status stands in China’s way of becoming the dominant regional power in East Asia. Chinese public opinion has already turned against North Korea, and leaders wonder whether a more reliable, pro-Chinese option to Kim might be installed. Since assuming power, Kim has gone after the generals and family members with the strongest ties to China.
One way to interpret Kim’s spat with U.S. President Donald Trump is that he is signaling to the Chinese that they shouldn’t try to take him down because he is willing to countenance “crazy” retaliation. In this view, Beijing is a more likely target for one of his nukes than is Seattle.
More radically, think of Kim as auditioning to the U.S., Japan, South Korea and India as a potential buffer against Chinese expansion. If he played his hand more passively and calmly, hardly anyone would think that such a small country had this capacity. By picking a fight with the U.S., he is showing the ability to deter just about anyone.
There is much more at the link, and of course I consider the “are these people really all so rational?” critique. You will note by the way that this inverts the usual argument that a longer time horizon means more cooperation. In this case a longer time horizon means more signaling and a more rambunctious form of signaling, precisely because the time horizon is long.
Would North Korea consider a first strike?
Vipin Narang says yes:
The strategy turns on Kim’s main calculation that the United States will say it’s not worth losing a major American city to get rid of him.
Of course he could not knock out a major American or allied target, but he could use them somewhere. And the use would boost his, uh…credibility. In fact Charles Murray is worried.
I think of the model this way. If Kim is irrational, we have obvious reason to worry, and of course a first strike could not be ruled out. Remember Pearl Harbor? (Or is that “Remember Pearl Harbor!”)
Alternatively, say all involved parties are fully rational in the selfish sense. Fully rational agents make purely forward-looking calculations. So if Kim used a nuke to kill a sparrow in North Korea, we would not attack because fear of losing an American city would far outweigh desire to retaliate for the loss of the sparrow.
How about one sparrow in the DMZ? In Japan? In the Arctic? In a Malaysian airport? Or maybe one sparrow, three sled dogs, and thirty Inuit?
At what point do we give it a go, and risk a poorly aimed North Korean ICBM being shot off into the sky?
What if Kim uses “only” a biological or chemical weapon, designed for minimum but noticeable impact, on a nearby country? You should think of Kim’s strategy space as a continuous variable, with some noise added of course.
Is the space of “boosts his credibility and domestic stature, but without too much upping the risk of massive American retaliation” really the empty set?
Maybe. Maybe not. I give it about one percent, which in expected value terms is still a real worry.
Strategic tennis grunts (from our email)
Hi guys:
I can pass along that there’s another angle to the grunts (having played a lot of tennis). The sound of the ball hitting the racket provides useful information, particularly for a mishit or a powerful shot — because you have to move up or back quickly to cope. For years, top tennis players have used grunts and shrieks to conceal this sound from their opponents (e.g. I always thought Sharapova, and Seles years ago, were prime offenders). There’s no need for such noises as a function of effort, or events like NBA games would sound much different. But the tennis authorities haven’t done anything about it.
In table tennis, where I have a very long involvement, the spin on the ball is tremendous in high-level play — so much so that a concealed dead ball (with no spin) is a very effective tactic because the opponent will err by responding to the spin that isn’t there. Years back, a totally dead racket covering was developed for this purpose; even worse, it tends to continue the spin so that the originator effectively gets the reverse back of what he put on the ball. A top US player with whom I grew up developed a style where he used only one side of the racket for both forehand and backhand, while frequently flipping between the spinny and dead sides of his racket that were colored the same. Players could hear the difference, however, as the dead side made a little thud when struck. His innovation was to stomp his foot on the floor each time he struck the ball (going beyond the norm of the time of just stomping on the serve). A subsequent regulatory change required rackets to have one red and one black side, to facilitate keeping track of which rubber covering is being used for a given shot.
Best,
Carl [Danner]
And here is my previous link to a new study of tennis grunts. And Carl sends along this video for table tennis. Sports aside, what other social practices fit this “misdirection” model?
The orca wars escalate, with special reference to the economics of fisheries
The orcas will wait all day for a fisher to accumulate a catch of halibut, and then deftly rob them blind. They will relentlessly stalk individual fishing boats, sometimes forcing them back into port.
Most chilling of all, this is new: After decades of relatively peaceful coexistence with cod and halibut fishers off the coast of Alaska, the region’s orcas appear to be turning on them in greater numbers.
“We’ve been chased out of the Bering Sea,” said Paul Clampitt, Washington State-based co-owner of the F/V Augustine.
Like many boats, the Augustine has tried electronic noisemakers to ward off the animals, but the orcas simply got used to them.
“It became a dinner bell,” said Clampitt.
John McHenry, owner of the F/V Seymour, described orca pods near Alaska’s Aleutian Islands as being like a “motorcycle gang.”
“You’d see two of them show up, and that’s the end of the trip. Pretty soon all 40 of them would be around you,” he said.
A report this week in the Alaska Dispatch News outlined instances of aggressive orcas harassing boats relentlessly — even refusing to leave after a desperate skipper cut the engine and drifted silently for 18 hours.
These are not Coasean orcas, or are they? And sperm whales are now in on the act:
Fishing lines are also being pillaged by sperm whales, the large square-headed whale best known as the white whale in Moby Dick.
“Since 1997, reports of depredation have increased dramatically,” noted a report by the Southeast Alaska Sperm Whale Avoidance Project.
A remarkable 2006 video by the Avoidance Project captured one of the 50,000 kg whales delicately shaking fish loose from a line. After a particularly heavy assault by sperm whales, fishers are known to pull up lines in which up to 90 per cent of the catch has disappeared or been mangled.
Here is the full story, with video, and further points of interest. For the pointer I thank the excellent Mark Thorson.