Arthur Perng — Writeups https://arthur.perng.com/writeups Long-form technical writeups by Arthur Perng. en Should I Take the Elevator or the Stairs? https://arthur.perng.com/writeups/elevator-or-stairs https://arthur.perng.com/writeups/elevator-or-stairs Thu, 01 Oct 2026 12:00:00 GMT It is a Software Engineer’s duty to spend hours to save seconds. Judging LLM development with Magic: the Gathering https://arthur.perng.com/writeups/mtg-benchmark https://arthur.perng.com/writeups/mtg-benchmark Tue, 08 Sep 2026 12:00:00 GMT A one-prompt Magic: The Gathering Commander test run on each new frontier model, with no re-prompting and no corrections — annotated answers, rules errors, and what the result does and does not show. The Sucker Punch problem, revisited https://arthur.perng.com/writeups/sucker-punch https://arthur.perng.com/writeups/sucker-punch Tue, 28 Jul 2026 12:00:00 GMT A game theory analysis of a Pokémon endgame: simultaneous decisions, incomplete information, and what changes once Sucker Punch starts running out of PP. Reverse-Engineering BASED’s RNG because I wanted 1st on the speedrun leaderboard https://arthur.perng.com/writeups/based-rng https://arthur.perng.com/writeups/based-rng Sat, 11 Jul 2026 12:00:00 GMT How I reverse engineered BASED’s Unity RNG, rebuilt its run generator in Python, and scanned the first 200 million seeds to find a 2:08 Set Seed run.