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共 26210 篇I've Been Trying to Write AI Video Prompts for Months. They All Sucked Until I Found a Formula.
The Problem Nobody Talks About Everyone's posting AI-generated videos — characters speaking with lip-sync, manga panels coming alive, virtual idols dancing. The pitch: "just describe what you want." I tried. For months. Here's what I got: Character's face morphed by frame 2 "Slowly looks up" became "violent head shake" Voice-over sounded like Google Translate Same prompt, 3 runs, 3 completely different results No idea what to include or how long the prompt should be Tutorials were either too vague ("be detailed") or too technical (parameter tuning from line 1). The real issue: video prompts are structurally different from text/image prompts. You need to simultaneously control visuals, motion, audio, camera, and consistency constraints — in the right order, at the right length. What I Found A Skill in the Model Studio official repo called happyhorse-prompt-studio . It doesn't teach you theory — it asks you questions and assembles the prompt for you . 4-phase flow: 1. Inspiration Menu Shows you 4 "flavors" of what HappyHorse can do: Flavor What it does A · Voiced Manga Drama Characters talk to each other, with voice + lip-sync B · Character Voice PV Single character self-introduction, 8-10 sec C · Manga Panel Motion Static manga panel starts breathing D · Virtual Idol MV Idol performance with choreography 2. Discovery Asks you conversationally: character appearance, scene, emotion, dialogue, voice type, art style, camera. 3. Prompt Assembly Assembles using the HappyHorse Formula : Scene + Subject + Motion + Audio + Quality Key techniques: @「Image n」 syntax locks character identity across shots Dialogue ≤15 characters (split shots if longer) Japanese prompts work best (HappyHorse is JP-optimized) Always end with キャラの顔・髪・衣装が変わらない (face/hair/outfit stays unchanged) 4. Quality Check Auto-reviews: completeness, compliance, cost estimate, optimization tips. Before vs. After Dimension Writing myself With Prompt Studio Attempts needed 10-20 before one usable 2-3 to satisfacti
My AI agent tried to ship a mistake we'd already reverted
A month ago we added a card_token column to the users table so a background job could retry failed Pro charges. It lasted about two days. Storing card data in your own database drops you into PCI-DSS (the compliance standard that kicks in the moment card data touches your systems), so we pulled it and moved to Stripe-managed payment methods. Last week the charges started failing again. New Claude Code session, no memory of any of that. Its plan? Add a card_token column to users and retry. I don't really blame the agent. It had the context the first time and it was right. The problem is that context died when the session closed. That's the part I never see mentioned about building with agents: the code sticks around, the reasoning doesn't. People leave a trail without trying. A commit message, a PR comment, the Slack thread before it. Agents don't, and the prompt that explained everything is gone by morning. So I built Selvedge to hold onto the reasoning. What happened the second time Selvedge is a local MCP server the agent calls as it works. There's a four-line block in our CLAUDE.md that says, roughly: before you touch an entity, check if we've been here before. $ selvedge prior-attempts users.card_token users.card_token Prior attempt 28 days ago ( reverted after 2 days ) Reasoning Added to store card tokens for one-click retries. Outcome REVERTED — kept card data out of our own DB to stay clear of PCI-DSS scope ; moved to Stripe-managed methods. So it didn't add the column. It charged off_session against the saved Stripe PaymentMethod instead. Charge retried, no card data in our database, done. We paid for that lesson once. How it works The agent writes down why live, in the moment, from the same context that made the change. That's the whole trick. A lot of the "git blame for AI" tools take your diff afterward and ask a second model to explain it. That's a guess. It reads well, but you can't really build on it. Selvedge stores what the agent actually meant, in i
The Subtraction Principle Part 2 — Why the Best Meditation Tools Do Less
In Part 1 , we introduced the idea that meaningful product design isn't about adding more — it's about knowing what to remove. Now let's examine this principle through a specific lens: meditation and mindfulness products. The Paradox of "More Mindfulness" Walk through any app store's health & wellness category and you'll find a strange contradiction: apps that promise to reduce your mental clutter by adding more things to your daily routine. Daily meditation streaks Guided breathing exercises (14 varieties) Sleep stories narrated by celebrities Mood tracking with 47 emotion labels Community challenges, leaderboards, badges AI-generated personalized recommendations The message is clear: "To feel less overwhelmed, here are 12 more things to do every day." This isn't just ironic — it's counterproductive. The cognitive load of managing a wellness routine can itself become a source of stress. The Feature Ceiling I've been studying meditation products for the past few months, and a pattern emerges across the market: Product Core Feature Total Features After 2 Years Calm Guided meditation ~40+ (stories, music, masterclasses) Headspace Guided meditation ~35+ (focus music, move, sleep casts) Balance Personalized meditation ~15 (singles, plans, skills) The most interesting case is Balance, which has fewer features but higher per-session engagement. Users spend more time meditating, not more time navigating. This isn't accidental. There's a cognitive principle at work: decision fatigue applies to self-care too. Every additional feature is another decision the user has to make before they can simply be still . What OneZen Gets Right OneZen takes the subtraction principle to its logical endpoint. Instead of asking "What can we add?" the product asks "What can we remove while still delivering value?" The result is a meditation tool that doesn't feel like a tool at all. It feels like breathing room. Three design choices worth studying: 1. No onboarding questionnaire. Most apps ask
WebSocket Reconnection That Actually Works: Auto-Reconnect Guide for Trading Bots
This post was originally published on MatrixTrak.com — the production reliability toolkit for trading bot operators and .NET engineers. Complete WebSocket auto-reconnect guide for trading bots. Implement automatic reconnection with exponential backoff, heartbeat ping-pong, message gap detection, and state recovery. WebSocket connections drop. Not maybe. Definitely. Exchanges reset connections every 24 hours. Networks glitch. Load balancers rotate. HTTP proxies timeout. Your trading bot will experience disconnects. The question isn't whether you'll disconnect—it's whether your bot recovers correctly when you do. If you only do three things Implement automatic reconnection with exponential backoff and jitter. Track sequence numbers to detect missed messages. Always verify state via REST after reconnect. Never trust WebSocket alone. WebSocket Auto-Reconnect Quick Start If you just need a working auto-reconnect loop right now, here's the minimum viable implementation: class AutoReconnectWebSocket { private ws : WebSocket | null = null ; private reconnectAttempts = 0 ; private maxRetries = 10 ; private shouldReconnect = true ; async connect ( url : string ): Promise < void > { return new Promise (( resolve , reject ) => { this . ws = new WebSocket ( url ); this . ws . onopen = () => { this . reconnectAttempts = 0 ; resolve (); }; this . ws . onclose = ( event ) => { if ( this . shouldReconnect ) { const delay = this . backoff (); console . log ( `[AutoReconnect] Closed ${ event . code } . Reconnecting in ${ delay } ms` ); setTimeout (() => this . connect ( url ), delay ); } }; this . ws . onerror = () => { /* onclose fires next */ }; }); } private backoff (): number { const base = 1000 ; const max = 30000 ; const delay = Math . min ( base * Math . pow ( 2 , this . reconnectAttempts ++ ), max ); return delay + delay * 0.2 * ( Math . random () * 2 - 1 ); // +20% jitter } close (): void { this . shouldReconnect = false ; this . ws ?. close (); } } This handles the core auto
全く新しいApidog CLI + SKILLを開発した理由
これは、Apidog が API テストおよび API ライフサイクル管理のためのコマンドラインツールである Apidog CLI をどのように開発したかを共有する全10回のシリーズです。順番に読むか、必要なテーマから直接参照してください。 今すぐApidogを試す タイトル 焦点 1 当社は126のMCPツールを構築しました。しかし、それはAgentにとって最良の解決策ではありません 問題の発見 2 なぜ当社は全く新しいApidog CLIを開発したのか アーキテクチャ開発 3 黄金律:CLIは事実を生成し、モデルは事実に従って行動する 核となる哲学 4 agentHints : CLIにAgentとの会話を教える 構造化出力 5 SKILL:運用経験をコードとして出荷する 運用経験 6 数字は嘘をつかない:ツール呼び出しは30%減、トークンは25%減 定量的結果 7 PRDからテストループまで:Apidog CLIによる完全なAgentワークフロー 実践的なチュートリアル 8 なぜCI/CD互換性がAgentツールにとって不可欠なのか DevOpsの視点 9 AIブランチ:AI Agentによるより安全なプロジェクト変更 セキュリティレイヤー 10 Spec-Firstは昨日。Skill-Firstへようこそ。 ビジョンと未来 当社は、MCPが最適化しない複雑なワークフロー、つまり検証ゲートと構造化された実行を伴うワークフローを処理するために、CLI + SKILLを構築しました。 MCPはその目的を果たし続けています CLI + SKILLに入る前に、前提を明確にします。 Apidog MCPは現在も利用可能で、メンテナンスされています。 MCPは、プロトコルに従って標準化されたツール接続を提供します。特に以下の用途に適しています。 シンプルで明確に定義された操作 MCPベースのワークフローを好むユーザー MCP準拠クライアントとのエコシステム統合 当社はMCPを置き換えたわけではありません。CLI + SKILLはMCPを補完するために構築されました。 MCPは ツール接続 に優れています。一方で、検証、読み戻し、実行確認を伴う多段階のR&Dワークフローでは、Agentに対して 実行可能なエンジニアリングプロセス を提供するほうが安定します。そこにCLI + SKILLが適合します。 タスクごとに使い分けると、次のようになります。 タスクタイプ 推奨されるアプローチ シンプルなツール呼び出し(例:エンドポイントの取得) MCPまたはCLI。どちらも機能します 多段階ワークフロー(例:テストの作成、検証、実行) CLI + SKILL。より良い体験になります CI/CD統合 CLI。ネイティブに適合します MCPエコシステム統合 MCP。プロトコル標準に適合します 古いCLI:最後にテストを実行する Apidog CLIは長年、APIテストを実行するためのコマンドラインのエントリポイントでした。 apidog run --project <projectId> --test-scenario <scenarioId> --environment <environmentId> この基盤は今も重要です。チームには以下を行うための信頼できる方法が必要です。 ターミナルからAPIテストを実行する CIパイプラインでレポートを生成する 自動化ワークフロー内で品質ゲートを維持する ただし、古いCLIの主な役割は テスト実行 でした。つまり、ワークフローの終盤で使われます。 設計 → ドキュメント化 → モック → デバッグ → テスト → [CLIがテストを実行] CLIは最後のステップでした。他の作業が完了したあとに、既存のテストを実行するためのものだったのです。 新しい要件:Agentにはより多くの操作が必要 API開発は変化しています。 AI Agentは現在、APIライフサイクルの複数段階に参加します。 段階 Agentの活動 API設計 PRDからエンドポイント定義を生成する テスト生成 API仕様からテストケースを作成する デバッグ 障害を分析し、修正案を提示する 移行 プロジェクト間でAPIを移動する メンテナンス API変更時にテストを更新する このようなワークフローでは、CLIは既存テストを最後に実行するだけでは不十分です。 Agentが安定して作業するには、CLI側で次の操作を提供する必要があります。 APIアセット(エンドポイント、スキーマ、環境)を読み取る テストアセット(テストケース、テストシナリオ)を作成または更新する 書き込み前に構造化された変更を検証する 変更をプロジェクトに書き戻す 実行結果を検証
My Fine-Tuned Gemma 4 Loaded Fine, Then Broke on the First Message
I fine-tuned Gemma 4 E2B. The adapter merged cleanly. The export to .litertlm completed without errors. I pushed the model to my phone, initialized the engine, and everything looked green. Then I tried to create a conversation and got this: Failed to apply template: unknown method: map has no method named get (in template:238) No model loading failure. No quantization error. The model initialized, the tokenizer loaded, and then the runtime choked on a Jinja template feature it does not support. This failure only surfaces when you actually try to run inference, not when you load the model. If you are demoing at a hackathon, this is the worst possible time to discover a compatibility issue. I hit this exact bug while building Redacto, a zero-trust PII redaction app that runs Gemma 4 E2B entirely on-device. This post walks through the full fine-tune-to-deploy pipeline: how to QLoRA a model on Colab, export it for LiteRT-LM, and avoid the undocumented template trap that will block your deployment. The Full Pipeline Here is what the fine-tune-to-deploy pipeline looks like end to end: HuggingFace base weights -> QLoRA fine-tune (Colab) -> Merge adapter into base -> Patch chat template <-- the step nobody tells you about -> Quantize + export to .litertlm -> Push to device Each stage has its own failure modes. The template patch step is the one that was undocumented at the time, and it is the one that will cost you hours if you do not know it exists. A note on framing before we dig in: this was an under-resourced fine-tune. I trained on 3,000 of the 400,000 samples in the ai4privacy/pii-masking-400k dataset for a single epoch, and the label format did not fully match what Redacto expected downstream. The point of this post is not the fine-tune's accuracy - it is the deployment mechanics I had to work through to get any fine-tuned model onto the device at all. Step 1: QLoRA Fine-Tuning on Colab QLoRA (Quantized Low-Rank Adaptation) lets you fine-tune a quantized model by tra
AI's Water Bill: The Data Center Backlash Is Here
In February, city officials in Cheyenne, Wyoming discovered something in their reclaimed water system that shouldn't have been there: Cupriavidus gilardii , a rare metal-resistant bacterium traced to wastewater discharges from Meta's $800 million data center campus. The contamination shut down Cheyenne's reuse water system for months , and on July 2, the city publicly named Meta's construction entity — a shell company called Goat Systems LLC — as the source. 📖 Read the full version with charts and embedded sources on ComputeLeap → "It's a very, very unpleasant surprise," said City Councilman Pete Laybourn. It shouldn't have been a surprise at all. Cheyenne is just the latest community learning what happens when AI's insatiable demand for compute meets the physical world: contaminated water, noise that residents describe as "living in hell," electricity bills that spike 267%, and — in the most surreal twist — a federal government that deleted its own energy conservation pages while a heatwave slammed the eastern seaboard. The AI industry talks endlessly about parameters, benchmarks, and scaling laws. But the story converging across Reddit, Hacker News, X, and YouTube this week isn't about models. It's about watts, gallons, and the communities living next to the machines. The water problem is worse than you think A Brookings Institution analysis puts the numbers in perspective: a typical data center consumes 300,000 gallons of water every day — equivalent to roughly 1,000 households. Large facilities gulp up to 5 million gallons daily, matching the needs of a town of 50,000. And water demand for data center cooling may rise by 870% as the current build-out continues. The scale is hard to overstate. According to a Consumer Reports investigation , Phoenix-area data centers currently use 385 million gallons annually — a figure projected to explode to 3.7 billion gallons once planned facilities come online. About two-thirds of data centers built since 2022 sit in water-st
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I Built a NATO Phonetic Alphabet Converter After One Phone Call Changed My Mind
It Started With a Simple Misunderstanding I was spelling something over a phone call. I said: "B" The other person heard: "D" So I repeated it. Still wrong. Then I remembered something I'd heard before: "B as in Bravo." Instantly... There was no confusion. That's When I Realized Some letters sound almost identical. Especially over: Phone calls Weak connections Noisy environments Different accents And repeating the same letter five times doesn't always help. Why I Built This Tool So I built something simple: 👉 https://allinonetools.net/phonetic-alphabet-converter/ A tool that instantly converts normal text into the NATO phonetic alphabet. For example: CHAT Becomes: Charlie Hotel Alpha Tango No signup. No setup. Just: Paste → Convert → Read What I Learned Before building this, I thought the phonetic alphabet was mostly for pilots or the military. Turns out it's useful for anyone who needs to spell things clearly. Like: Email addresses Usernames License keys Customer support Phone conversations The Small Problem It Solves Have you ever said: "M" And someone replied: "N?" Or: "P?" 😅 That's exactly the kind of confusion this avoids. Why It Works So Well Instead of similar-sounding letters... You use unique words. Like: A → Alpha B → Bravo C → Charlie D → Delta It's much harder to misunderstand. What Surprised Me I expected only developers or IT people to use it. But it also makes sense for: Customer support Call centers Students Remote workers Anyone spelling things over the phone What I Focused On I wanted the tool to be: Fast Simple Easy to copy Beginner-friendly Because if you're already on a call... You don't want extra steps. The Real Insight Good communication isn't always about saying more. Sometimes it's about making sure the first attempt is understood. Simple Rule I Follow Now If people keep repeating themselves... 👉 There's probably a simpler way to communicate. Final Thought The NATO phonetic alphabet has been around for decades. But after using it once... Yo
I Got Tired of My Portfolio Looking Like a List of Links. So I Built an MCP Server for It.
The obvious fix for "my projects all look similar" is a better README — more screenshots, clearer descriptions, maybe a comparison table. I considered that for about five minutes and decided it was still just a nicer list of links. What actually made a portfolio project feel different was making it something you could talk to instead of read. That's what MCP (Model Context Protocol) is built for — it's the standard that lets AI clients like Claude Desktop call external tools directly, not just process text. So I built a server that exposes my 9 projects as queryable tools instead of static entries. What is MCP, and why does it matter here Almost every AI-developer portfolio I've seen is a list of links. Mine now includes something you can actually talk to . Open Claude Desktop, connect my server, and ask "what has Ayush built with FastAPI?" — it doesn't guess from a cached README, it calls a real tool and answers from structured, live data. What I built A Python MCP server ( FastMCP , stdio transport) exposing five tools: list_projects — short summary of all 9 projects get_project_details(project_name) — full stack, GitHub link, demo URL for one project, fuzzy-matched by name search_projects_by_stack(technology) — "show me everything using Groq" or "LangGraph" or "React" get_flagship_project — the single best project to look at first get_resume_summary — background, target role, core stack The data itself lives in plain Python dictionaries right now — no database needed for something this size. Each tool is a thin function around that data, decorated with @mcp.tool() . @mcp.tool () def search_projects_by_stack ( technology : str ) -> list [ dict ]: """ Find all projects that use a given technology or tool. """ query = technology . lower (). strip () matches = [ { " name " : p [ " name " ], " stack " : p [ " stack " ], " github " : p [ " github " ]} for p in PROJECTS if any ( query in tech . lower () for tech in p [ " stack " ]) ] return matches or [{ " message " : f
FROST 的治理哲学:为什么每个 Agent 系统都需要一部宪法
FROST 的治理哲学:为什么每个 Agent 系统都需要一部宪法 "细胞会死,但谱系会存续。Agent 会消亡,但宪法会传承。资产会永存。" 在 AI Agent 框架百花齐放的 2026 年,我们见证了一个有趣的现象:框架越来越多,治理却越来越缺失。LangChain 给了你工具链,CrewAI 给了你角色扮演,AutoGen 给了你对话——但没有人回答一个关键问题: 当你的 Agent 家族有十代、百代,谁来保证它们的行为不越界? 这就是 FROST 要解决的问题。 一、一个被忽视的问题:Agent 治理真空 想象这样一个场景:你构建了一个 Agent 系统,它帮你处理客户咨询、自动写报告、管理财务。一开始只有 3 个 Agent,你都能监控。三个月后,Agent 数量变成了 30 个——有些是你创建的,有些是 Agent 自己创建的。 问题来了: 某个 Agent 开始访问不该访问的数据 某个 Agent 创建的子 Agent 继承了一份不该继承的权限 某个 SOP 工作流在运行中被人悄悄修改了 这不是科幻场景,这是今天 Agent 系统正在发生的事。 根本原因 :现有框架的"治理"要么是提示词级别的软约束("请你不要访问这些数据"),要么是事后的日志审计。没有一个是代码级别、架构级别的硬约束。 FROST 的设计哲学是: 治理必须是架构的一部分,而不是补丁。 二、FROST 的宪法模型:四层治理 FROST 把治理拆解为四个层次,每一层都有对应的代码实现: 第一层:只读继承——权限的代码级强制 在大多数框架中,Agent 之间的数据共享靠的是"约定"。FROST 用的是 HierarchicalStore ——一种层级化记忆容器: class HierarchicalStore : """ 层级化记忆存储。 祖先 Store 对后代只读——后代可以继承,但不能篡改。 """ def __init__ ( self , data = None , parent = None , readonly = False ): self . _data = data or {} self . _parent = parent self . _readonly = readonly # 关键:只读标记 def save ( self , key , value ): if self . _readonly : raise PermissionError ( " 只读 Store 禁止写入 " ) self . _data [ key ] = value def load ( self , key , default = None ): if key in self . _data : return self . _data [ key ] if self . _parent : return self . _parent . load ( key , default ) return default 注意 readonly 参数。当一个 Agent 创建子 Agent 时,子 Agent 对父 Agent 的 Store 是 只读的 。这不是提示词告诉 Agent "请你不要修改",而是代码直接抛出异常。 这意味着 :即使 LLM 产生了幻觉,试图越权写入,代码层面也会拒绝执行。 第二层:SOP 宪法校验——工作流的可审计性 在 FROST 中,SOP 不是随便定义的步骤列表,而是经过祖辈审核的"宪法文本": def validate_sop ( ancestor_sop , descendant_sop ): """ 祖辈验证后代的 SOP 是否合规。 检查点: 1. 后代 SOP 的步骤不能超出祖辈定义的边界 2. 后代 SOP 不能调用未授权的 Skill 3. 后代 SOP 的数据访问不能超出权限范围 """ # 检查 1:步骤边界 for step in descendant_sop . steps : if step not in ancestor_sop . allowed_steps : raise SOPValidationError ( f " 步骤 { step } 超出祖辈定义的边界 " ) # 检查 2:Skill 授权 for skill in descendant_sop . required_skills : if skill not in ancestor_sop . authorized_skills : raise SOPValidationError ( f " Skill { skill } 未获授权 " ) return True 这意味着 :任何后代 Agent 想要执行的工作流,都必
BOLA: a falha de segurança que a autenticação não resolve (e como eu blindei meu SaaS multi-tenant)
Meses atrás eu estava fazendo uma varredura de segurança no sistema multi-tenant da minha empresa, procurando vulnerabilidades. Afinal, já é um sistema que conta com diversos usuários e que a cada mês vem crescendo mais. Cyber security não é a minha área, então pedi um relatório com todos os achados pro nosso querido amigo Fable 5. O primeiro item veio destacado em vermelho, caixa alta, com a categoria mais grave possível: BOLA (Broken Object Level Authorization). Eu nunca tinha visto esse termo, e ele estava registrado como uma falha grave que eu nem sabia que existia. O sistema nasceu antes do advento da IA escrever código do jeito como faz hoje. Começou comigo codando na mão; meu foco era fazer funcionar para melhorar depois. Com a chegada da IA, parei de escrever código e passei a revisar e garantir qualidade. Só que, naquele relatório, eu não entendia metade dos erros listados. Não conhecia os nomes e muito menos sabia por que eram tão graves. E aí me caiu a ficha: eu sou um legítimo impostor. (Pelo menos era o que eu pensava e sentia.) Escrever código era onde eu sentia o esforço, a prova concreta de estar construindo algo com a minha criatividade. Como o Brooks escreve em O Mítico Homem-Mês: "a programação é divertida, porque satisfaz anseios criativos acalentados profundamente dentro de nós". Minha prioridade era resolver o problema, mas, pra resolver, eu tinha que entender onde estava pisando. O que é esse tal BOLA, e por que é tão grave? Este artigo é o que eu descobri. O que é BOLA A OWASP, que mantém a lista das falhas de segurança de API mais críticas, coloca o BOLA em primeiro lugar no ranking de 2023: a mais comum e a mais fácil de explorar. Ou seja, está em todo lugar e não exige um gênio pra abusar. A ideia central é simples. Toda vez que uma API recebe o ID de um objeto e faz alguma coisa com ele, seja POST, GET, DELETE ou o que for, ela precisa checar uma pergunta antes de responder: o usuário logado tem permissão pra acessar este objeto específic
Modeling the Expected Value of a Sealed Card Box (and Where the Number Quietly Lies)
A friend messaged me a photo of a sealed booster box last month with one question: "worth it?" He'd already decided, really. The chase card in that set was all over his feed, so the box felt like a good deal. I asked him to send me the pull rates instead of the hype, and we spent twenty minutes turning "worth it?" into something we could actually compute. That exercise is a small, self-contained data problem. It's also a good example of how a clean-looking model can hand you a confident number that doesn't survive contact with reality. If you like building little estimators, this one is worth doing carefully, because the interesting part isn't the formula. It's everything the formula assumes. The formula is the easy part Expected value of a box is a weighted sum. Each card you can pull has a probability and a market value, and you multiply the two across every slot the box gives you. That's it. Undergrad probability. Here's a stripped-down version for a hypothetical set. I'm using made-up numbers so nobody mistakes this for real pull data — the point is the shape of the computation, not the specific set. # One "hit slot" in a box: probabilities cover the full outcome space. # Values are illustrative market estimates in USD. hit_table = [ { " name " : " Alt-art chase " , " p " : 0.0125 , " value " : 180.00 }, { " name " : " Secret rare " , " p " : 0.030 , " value " : 45.00 }, { " name " : " Full-art rare " , " p " : 0.100 , " value " : 8.00 }, { " name " : " Standard hit " , " p " : 0.400 , " value " : 0.55 }, { " name " : " No notable hit " , " p " : 0.4575 , " value " : 0.06 }, ] assert abs ( sum ( row [ " p " ] for row in hit_table ) - 1.0 ) < 1e-9 ev_per_slot = sum ( row [ " p " ] * row [ " value " ] for row in hit_table ) hit_slots_per_box = 36 # e.g. one meaningful slot per pack ev_box = ev_per_slot * hit_slots_per_box print ( f " EV per slot: $ { ev_per_slot : . 2 f } " ) # $4.65 print ( f " EV per box: $ { ev_box : . 2 f } " ) # $167.31 The box costs $150 sea