The blog post "Kelly Can't Fail," authored by John Mount and published on the Win-Vector LLC website, delves into the oft-misunderstood concept of the Kelly criterion, a formula used to determine optimal bet sizing in scenarios with known probabilities and payoffs. The author meticulously dismantles the common misconception that the Kelly criterion guarantees success, emphasizing that its proper application merely optimizes the long-run growth rate of capital, not its absolute preservation. He accomplishes this by rigorously demonstrating, through mathematical derivation and illustrative simulations coded in R, that even when the Kelly criterion is correctly applied, the possibility of experiencing substantial drawdowns, or losses, remains inherent.
Mount begins by meticulously establishing the mathematical foundations of the Kelly criterion, illustrating how it maximizes the expected logarithmic growth rate of wealth. He then proceeds to construct a series of simulations involving a biased coin flip game with favorable odds. These simulations vividly depict the stochastic nature of Kelly betting, showcasing how even with a statistically advantageous scenario, significant capital fluctuations are not only possible but also probable. The simulations graphically illustrate the wide range of potential outcomes, including scenarios where the wealth trajectory exhibits substantial declines before eventually recovering and growing, emphasizing the volatility inherent in the strategy.
The core argument of the post revolves around the distinction between maximizing expected logarithmic growth and guaranteeing absolute profits. While the Kelly criterion excels at the former, it offers no safeguards against the latter. This vulnerability to large drawdowns, Mount argues, stems from the criterion's inherent reliance on leveraging favorable odds, which, while statistically advantageous in the long run, exposes the bettor to the risk of significant short-term losses. He further underscores this point by contrasting Kelly betting with a more conservative fractional Kelly strategy, demonstrating how reducing the bet size, while potentially slowing the growth rate, can significantly mitigate the severity of drawdowns.
In conclusion, Mount's post provides a nuanced and technically robust explanation of the Kelly criterion, dispelling the myth of its infallibility. He meticulously illustrates, using both mathematical proofs and computational simulations, that while the Kelly criterion provides a powerful tool for optimizing long-term growth, it offers no guarantees against substantial, and potentially psychologically challenging, temporary losses. This clarification serves as a crucial reminder that even statistically sound betting strategies are subject to the inherent volatility of probabilistic outcomes and require careful consideration of risk tolerance alongside potential reward.
Nicholas Barker's blog post introduces Clay, a declarative UI layout library he authored. Clay distinguishes itself by focusing solely on layout, deliberately omitting features like rendering or state management, allowing it to integrate seamlessly with various rendering technologies like HTML, Canvas, WebGL, or even server-side SVG generation. This separation of concerns promotes flexibility and allows developers to choose the rendering method best suited for their project.
The library employs a constraint-based layout system, allowing developers to define relationships between elements using a concise and expressive syntax. These constraints, expressed through functions like center, match, above, and below, govern how elements are positioned and sized relative to one another. This approach facilitates dynamic and responsive layouts that adapt to different screen sizes and orientations.
Clay’s API is designed for clarity and ease of use, promoting a declarative style that simplifies complex layout definitions. Instead of manually calculating positions and dimensions, developers describe the desired relationships between elements, and Clay's engine handles the underlying calculations. This declarative approach enhances code readability and maintainability, reducing the likelihood of layout-related bugs.
The post provides illustrative examples demonstrating how to use Clay’s functions to achieve various layout arrangements. These examples showcase the library's versatility and its ability to handle both simple and intricate layouts. The author emphasizes the library's small size and efficiency, making it suitable for performance-critical applications. Further, its focused nature avoids the "kitchen sink" problem common in larger UI libraries, keeping the API lean and intuitive. By concentrating solely on layout, Clay avoids feature bloat and remains a lightweight, specialized tool that can be readily integrated into diverse projects. The post concludes by inviting readers to explore the library's source code and documentation, encouraging contributions and feedback from the community.
The Hacker News post titled "Clay – UI Layout Library" discussing Nic Barker's new layout library has generated a modest amount of discussion, focusing primarily on comparisons to existing layout systems and some initial impressions.
Several commenters immediately draw parallels to other layout tools. One points out the similarities between Clay and the CSS Flexbox model, suggesting that Clay essentially replicates Flexbox functionality. This comparison is echoed by another user who expresses a preference for leveraging the browser's native Flexbox implementation, citing concerns about potential performance overhead with a JavaScript-based solution like Clay.
Another commenter delves into a more detailed comparison with Yoga, a popular cross-platform layout engine. They highlight that Clay adopts a constraint-based approach similar to Yoga but implemented in WebAssembly for potential performance benefits. The comment emphasizes Clay's novel use of “streams” to update layout properties, contrasting it with Yoga's more traditional recalculation methods. This distinction sparks further discussion about the potential advantages and disadvantages of stream-based layout updates, with some speculating about its impact on performance and ease of use in complex layouts.
Performance is a recurring theme. One comment questions the actual performance gains of using WebAssembly for layout calculations, pointing to potential bottlenecks in JavaScript interoperability. This raises a larger discussion about the optimal balance between native browser capabilities and JavaScript-based libraries for layout management.
A few comments focus on the specific design choices within Clay. One user questions the decision to expose low-level layout primitives rather than providing higher-level abstractions, leading to a conversation about the trade-off between flexibility and ease of use in a layout library. Another comment highlights the benefit of Clay’s explicit sizing model, suggesting it helps avoid common layout issues encountered in other systems.
Overall, the comments demonstrate a cautious but intrigued reception to Clay. While acknowledging the potential benefits of its WebAssembly implementation and novel stream-based updates, commenters express reservations about its performance relative to native browser solutions and question some of its design choices. The discussion ultimately revolves around the ongoing search for the ideal balance between performance, flexibility, and ease of use in UI layout management.
Nullboard presents a minimalist, self-contained Kanban board implementation entirely within a single HTML file. This means it requires no server-side components, databases, or external dependencies to function. The entire application logic, data storage, and user interface are encapsulated within the HTML document, leveraging the browser's local storage capabilities for persistence.
The board's core functionality revolves around managing tasks represented as cards. Users can create new cards, edit their content, and move them between user-defined columns representing different stages of a workflow (e.g., "To Do," "In Progress," "Done"). This movement simulates the progression of tasks through the workflow visualized on the Kanban board.
Data persistence is achieved using the browser's localStorage mechanism. Whenever changes are made to the board's state, such as adding, modifying, or moving a card, the updated board configuration is automatically saved to the browser's local storage. This ensures that the board's state is preserved across browser sessions, allowing users to return to their work where they left off.
The user interface is simple and functional. It consists of a series of columns represented as visually distinct sections. Within each column, tasks are displayed as cards containing editable text. Users interact with the board through intuitive drag-and-drop actions to move cards between columns and in-place editing to modify card content. The minimalist design prioritizes functionality over elaborate styling, resulting in a lightweight and fast-loading application.
Because Nullboard is entirely self-contained within a single HTML file, it offers several advantages, including ease of deployment, portability, and offline functionality. Users can simply download the HTML file and open it in any web browser to start using the Kanban board without any installation or configuration. This makes it highly portable and accessible from any device with a web browser. Furthermore, the offline functionality allows users to continue working even without an internet connection, with changes being saved locally and synchronized when connectivity is restored. This self-contained nature also simplifies backup and sharing, as the entire application state is contained within a single file.
The Hacker News post for Nullboard, a single HTML file Kanban board, has several comments discussing its merits and drawbacks.
Several commenters appreciate the simplicity and self-contained nature of Nullboard. One user highlights its usefulness for quick, local task management, especially when dealing with sensitive data that they might hesitate to put on a cloud service. They specifically mention using it for organizing personal tasks and small projects. Another commenter echoes this sentiment, praising its offline capability and the absence of any server-side components. The ease of use and portability (simply downloading the HTML file) are also repeatedly mentioned as positive aspects.
The discussion then delves into the limitations of saving data within the browser's local storage. Commenters acknowledge that while convenient, this method isn't robust and can be lost if the browser's data is cleared. One user suggests potential improvements, such as adding functionality to export and import the board's data as a JSON file, allowing for backup and transfer between devices. This suggestion sparks further discussion about other potential features, including the possibility of syncing with cloud storage services or using IndexedDB for more persistent local storage.
Some commenters also compare Nullboard to other similar minimalist project management tools. One user mentions using a simple Trello board for similar purposes, while another suggests exploring Taskwarrior, a command-line task management tool. This comparison highlights the variety of simple project management tools available and the different preferences users have.
The lack of collaboration features is also noted. While acknowledged as a limitation, some view this as a benefit, emphasizing the focus on individual task management. One commenter also notes the project's similarity to a "poor man's Trello," further highlighting its basic functionality.
Finally, some technical aspects are touched upon. One commenter inquires about the framework used, to which the creator (also present in the comments) responds that it's built with Preact. This clarifies the technical underpinnings of the project and showcases its lightweight nature. Another comment delves into the specific usage of local storage and how refreshing the page retains the data.
Liz Pelly's Harper's Magazine article, "The Ghosts in the Machine," delves into the shadowy world of "fake artists" proliferating on music streaming platforms, particularly Spotify. Pelly meticulously details the phenomenon of music created not by singular, identifiable artists, but by often anonymous individuals or teams working for production houses, sometimes referred to as "music mills." These entities churn out vast quantities of generic, mood-based instrumental music, frequently categorized into playlists like "lo-fi hip hop radio - beats to relax/study to" or other ambient soundscapes designed for specific activities.
Pelly argues that this trend represents a shift away from the traditional conception of musical artistry. Instead of focusing on individual expression, innovation, or personal narratives, these "ghost artists" prioritize creating functional, commercially viable soundtracks for everyday life. The article suggests that this commercially driven approach, facilitated by Spotify's algorithms and playlist curation system, incentivizes quantity over quality and prioritizes algorithmic discoverability over artistic integrity.
The piece further explores the economic implications of this system, suggesting that while a select few production houses may be reaping substantial profits, the actual creators of the music often remain uncredited and poorly compensated for their work. This anonymity further obfuscates the origin and true nature of the music consumed by millions, raising ethical questions about transparency and fair compensation within the streaming economy.
Pelly paints a picture of a musical landscape increasingly dominated by commercially driven, algorithmically optimized soundscapes, created by unseen individuals working within a system that prioritizes passive consumption over artistic engagement. She posits that this trend represents a fundamental transformation of the music industry, where the traditional notion of the artist is being eroded, replaced by a nebulous, often anonymous production process that favors quantity, algorithmic compatibility, and commercial viability over artistic individuality. This, the article implies, could have long-term consequences for the future of musical creation, potentially stifling innovation and further marginalizing genuine artists struggling to compete in an increasingly saturated and algorithm-driven marketplace. The rise of these "ghost artists" ultimately reflects a broader trend within the digital economy, where automated processes and algorithmic curation are increasingly shaping cultural production and consumption.
The Hacker News post titled "Ghost artists on Spotify" linking to a Harper's article about the prevalence of ghostwriters and algorithmic manipulation in the music industry generated a moderate discussion with several insightful comments. Many commenters engaged with the core issues presented in the article, exploring different facets of the situation.
A recurring theme was the tension between artistic integrity and commercial pressures. Several commenters expressed concern that the increasing industrialization of music production, exemplified by the use of ghostwriters and algorithmic optimization, was leading to a homogenization of sound and a decline in artistic originality. One commenter poignantly described the phenomenon as creating "musical product" rather than art. This sentiment was echoed by others who lamented the loss of the "human element" in music creation.
Another key discussion point revolved around the exploitation of musicians within this system. Commenters acknowledged the difficult position many artists find themselves in, forced to compromise their artistic vision to chase algorithmic trends and secure a livelihood. The opacity of the music industry and the power dynamics between artists and streaming platforms like Spotify were also highlighted, with some commenters suggesting that artists are often left with little bargaining power and inadequate compensation for their work.
Several commenters also discussed the role of algorithms and streaming platforms in shaping musical tastes and trends. Some argued that the algorithmic curation of playlists and recommendations reinforces existing biases and promotes a narrow range of sounds, further contributing to the homogenization of music. Others pointed out the potential for manipulation, where songs are engineered to appeal to algorithmic preferences rather than artistic merit.
The ethical implications of ghostwriting were also debated. While some commenters argued that it's a legitimate form of collaboration, others expressed concerns about the lack of transparency and the potential for exploitation, particularly for up-and-coming artists. The discussion touched on the issue of authorship and the value placed on originality in artistic creation.
Finally, a few commenters offered alternative perspectives, suggesting that the use of ghostwriters and algorithmic optimization is simply a reflection of evolving trends in the music industry and not necessarily a negative development. They argued that these practices can help artists reach a wider audience and that ultimately, the listener's enjoyment is the most important factor.
While there wasn't a large volume of comments, the discussion offered a nuanced and thoughtful examination of the complex issues surrounding ghostwriting, algorithmic manipulation, and the changing landscape of the music industry. The comments highlighted the challenges faced by artists in the digital age and sparked a conversation about the future of music creation and consumption.
In a revelation that challenges long-held assumptions about the dietary habits of seemingly innocent, nut-loving squirrels, a recent scientific observation documented in the esteemed publication, Mammalian Biology, unveils a decidedly carnivorous aspect to their behavior. Researchers meticulously chronicled instances of red squirrels, specifically Sciurus vulgaris, engaging in the active pursuit and consumption of animal flesh. While anecdotal evidence and previous studies hinted at opportunistic scavenging of meat, these meticulously documented observations provide concrete evidence of deliberate predation.
The groundbreaking research, conducted in the Yukon territory of Canada, details multiple incidents of red squirrels strategically hunting and consuming snowshoe hares. These observations were not isolated events but rather a recurring phenomenon observed over an extended period, suggesting a more ingrained behavioral pattern than previously understood. The documented hunting strategy involved the squirrels ambushing significantly larger snowshoe hares, often targeting vulnerable juveniles or individuals weakened by harsh winter conditions. This predatory behavior showcases an unexpected level of calculated aggression and adaptability in these typically herbivorous rodents.
The scientific community postulates several potential motivations for this carnivorous dietary shift. The prevailing hypothesis suggests that the harsh, resource-scarce environment of the Yukon, particularly during the challenging winter months, compels the squirrels to expand their dietary repertoire to ensure survival. The high nutritional value of meat, specifically the readily available protein and fat, offers a significant energetic advantage over traditional plant-based food sources, allowing the squirrels to better withstand the extreme cold and limited foraging opportunities. This observed dietary flexibility highlights the remarkable adaptability of red squirrels and their capacity to exploit available resources, even those traditionally outside their established ecological niche. This newly acquired understanding of red squirrel dietary habits compels a reevaluation of their role within the complex ecosystem of the Yukon and underscores the dynamic nature of predator-prey relationships in the face of environmental pressures.
The Hacker News post titled "Squirrels Caught Hunting and Eating Meat" (linking to a Gizmodo article) generated several comments discussing the observation of squirrels consuming meat. Many commenters pointed out that squirrels eating meat is not a new phenomenon, with numerous anecdotes of personal observations. Several people shared stories of squirrels eating baby birds, bird eggs, insects, and even roadkill.
One compelling thread highlighted the opportunistic nature of squirrels as omnivores. Commenters argued that labeling this behavior as "hunting" might be a mischaracterization. They suggested that squirrels are more likely scavengers, taking advantage of readily available food sources, including carrion or already deceased animals, rather than actively pursuing and killing prey. This distinction led to a discussion about the definition of hunting and whether opportunistic feeding qualifies.
Another interesting point raised was the role of nutritional needs in driving this behavior. Some commenters speculated that squirrels might turn to meat for specific nutrients, such as protein or calcium, particularly during periods of food scarcity or increased demand, such as pregnancy or lactation.
Some commenters expressed skepticism about the novelty of the observation reported in the linked article, suggesting that scientists may have overlooked this behavior previously or that it simply wasn't considered noteworthy until recently. Others countered that while anecdotal evidence existed, systematic documentation and study of this behavior in specific squirrel populations might offer valuable scientific insights.
Finally, a few humorous comments emerged, with users joking about the potential dangers of "meat-eating squirrels" or making light of their own encounters with squirrels exhibiting aggressive or unexpected behavior.
Summary of Comments ( 120 )
https://news.ycombinator.com/item?id=42466676
The Hacker News comments discuss the limitations and practical challenges of applying the Kelly criterion. Several commenters point out that the Kelly criterion assumes perfect knowledge of the probability distribution of outcomes, which is rarely the case in real-world scenarios. Others emphasize the difficulty of estimating the "edge" accurately, and how even small errors can lead to substantial drawdowns. The emotional toll of large swings, even if theoretically optimal, is also discussed, with some suggesting fractional Kelly strategies as a more palatable approach. Finally, the computational complexity of Kelly for portfolios of correlated assets is brought up, making its implementation challenging beyond simple examples. A few commenters defend Kelly, arguing that its supposed failures often stem from misapplication or overlooking its long-term nature.
The Hacker News post "Kelly Can't Fail" (linking to a Win-Vector blog post about the Kelly Criterion) generated several comments discussing the nuances and practical applications of the Kelly Criterion.
One commenter highlighted the importance of understanding the difference between "fraction of wealth" and "fraction of bankroll," particularly in situations involving leveraged bets. They emphasize that Kelly Criterion calculations should be based on the total amount at risk (bankroll), not just the portion of wealth allocated to a specific betting or investment strategy. Ignoring leverage can lead to overbetting and potential ruin, even if the Kelly formula is applied correctly to the initial capital.
Another commenter raised concerns about the practical challenges of estimating the parameters needed for the Kelly Criterion (specifically, the probabilities of winning and losing). They argued that inaccuracies in these estimates can drastically affect the Kelly fraction, leading to suboptimal or even dangerous betting sizes. This commenter advocates for a more conservative approach, suggesting reducing the calculated Kelly fraction to mitigate the impact of estimation errors.
Another point of discussion revolves around the emotional difficulty of adhering to the Kelly Criterion. Even when correctly applied, Kelly can lead to significant drawdowns, which can be psychologically challenging for investors. One commenter notes that the discomfort associated with these drawdowns can lead people to deviate from the strategy, thus negating the long-term benefits of Kelly.
A further comment thread delves into the application of Kelly to a broader investment context, specifically index funds. Commenters discuss the difficulties in estimating the parameters needed to apply Kelly in such a scenario, given the complexities of market behavior and the long time horizons involved. They also debate the appropriateness of using Kelly for investments with correlated returns.
Finally, several commenters share additional resources for learning more about the Kelly Criterion, including links to academic papers, books, and online simulations. This suggests a general interest among the commenters in understanding the concept more deeply and exploring its practical implications.