Building an AI lineup optimizer for a Discord esports bot (the algorithm, not the hype)

Every esports team captain has done this by hand at least once: open Discord, scroll through a dozen "I can play Thursday after 8" messages, cross-reference them against who plays Tank versus DPS, remember that one of your DPS is actually a sub, and try to assemble a starting five that can actually scrim tonight. It takes fifteen minutes, you get it slightly wrong, and you do it again the next day. I build Supatimer , a free Discord bot for competitive gaming teams, and "generate the lineup for me" was the single most requested feature. This post is about how the lineup optimizer actually works, why it is genuinely AI (and not in the marketing sense), and where a large language model fits in versus where it absolutely does not. "AI" is doing a lot of work in this industry Half the Discord bots on the market slapped "AI" on their landing page the week ChatGPT launched. Usually it means there is a chatbot command somewhere that proxies to an LLM. That is fine, but it is not what your team needs when it is 7:45pm and you have a scrim at 8. There are two honest definitions of AI worth separating: Search and optimization - the classical branch. Constraint satisfaction, combinatorial optimization, planning. This is the part of AI that solves "given these rules and these resources, find the best valid arrangement." Machine learning / LLMs - the statistical branch. Pattern recognition, generation, extraction from unstructured text. The lineup problem is squarely a problem for the first kind. So that is what I built first. The lineup problem, stated precisely Strip away the gaming context and a lineup is a constrained assignment problem: You have N players , each with a set of roles they can fill (Tank, DPS, Support, IGL, and so on). Each player has an availability signal for a given time block (available, maybe, unavailable). Each player has a roster status (starter, substitute, trial). The game defines a required composition : Overwatch 2 wants 1 Tank, 2 DPS, 2 Support. Va