map veto game theory

Ban and pick maps against a minimax AI. The AI plays the game-theoretically optimal veto. Can you beat it?

Each team has hidden win rates on each map. The veto follows the CS Major format:

ban → ban → ban → ban → pick → pick → decider

Choose difficulty:

Casual

You see both teams' win rates

Ranked

You see only your own win rates

Pro

You see nothing. Pure reads.

BAN PHASE 1

Ban a map.

your turn

Veto Complete

here's what you're playing

your expected win %

AI expected win %

random veto avg

The AI uses minimax on the full veto tree. With 7 maps and 7 sequential decisions, the tree has at most 7! = 5,040 leaves — small enough to solve exactly.

At each decision point, the acting team picks the map that maximizes (or minimizes) their expected match win rate across the final 3 maps played (pick + pick + decider).

The "random veto" baseline averages over all possible veto sequences to show what you'd get with no strategy at all.