Streaks

Rules

Streaks is played on three arms reaching out from a shared center. and take turns building outward on any arm that still has room, 4 slots per arm.

How many slots you can fill depends on the streak — the run of matching color — already at the far end of the arm you pick: even-length (including a bare arm) allows up to 2, odd-length allows just 1. Either way, using the full amount is optional.

The current allowance for each arm is shown right on the board.

Whoever is forced to place the piece that fills the very last open slot, anywhere on the board, loses. Who moves first alternates each new game.

New to this one? Medium is a good place to start — it plays loosely through the first half of the board and then starts trying in earnest once things are more than half full, so there's real room to get ahead early.

Controls

The three arms are named Top, Right, and Left, matching how they sit around the board.

With a mouse or touchscreen: tap the "1" or "2" wedge on an arm's next open slot to place that many.

With a keyboard: type an arm into the box below the board — "top," or just "t" — then press Enter or Play. If that arm currently allows either 1 or 2, add the count too, like "top 2" or "t 1" — if only one count is legal right now, the arm name alone is enough.

Type status (or just the start of it, like "sta") and press Enter or Play at any time — even when it isn't your turn — to have all three arms and their current allowances read back to you.

Don't want the keyboard box taking up screen space? There's a "Keyboard move-entry" checkbox under Settings that hides it — on by default with a mouse or trackpad, off by default on touch, and remembered separately for each device you play on.

Roots

Streaks is a Nim-family subtraction game — three shared piles (arms) instead of one, and how many pieces you're allowed to add depends on the streak already there. Classic subtraction games (take 1 or 2 from a pile, last player unable to move loses) are one of the best-studied corners of Nim theory.

Its stricter sibling, Odds and Evens, removes the choice and forces an exact count instead.

Under the hood

Streaks doesn't have a single win line to chase. Three arms fill up with pieces over the course of the game — four slots each, twelve in total — and whoever is forced to place the piece that completes the very last open slot loses: a misère-style rule, the opposite of most of the site's other games, where finishing the board is what you're trying to avoid, not cause. Each turn you choose one arm and add one or two of your own color to its growing end, and how many you're allowed to add depends on the trailing streak already there: an even-length run lets you add up to two, an odd-length run only lets you add one. Managing that parity, on three arms at once, is the entire game.

The difficulty tiers here don't work the way they do elsewhere on the site. Since the full exact search is cheap enough to run every single time (the whole game solves via straightforward memoized minimax), there's no meaningful "search fewer moves ahead" knob to turn. Instead, Easy and Medium are gated by how much of the board is left. Easy plays almost entirely at random until the board is down to its very last open arm, and even then it's a 25% chance to notice a trap and only a 15% chance to notice it shouldn't hand the game to you itself — low enough that it usually just plays on regardless. Medium plays randomly through the first half of the game and only starts actually trying — taking the exact-solved best move 80% of the time — once the board has less than half its slots left. That second threshold was measured, not guessed: an earlier version let Medium start trying sooner, and its own block-detection so rarely mattered by that point that Medium ended up playing just as well as Hard in practice. Hard skips the gating entirely — every turn, a quick one-ply check asks whether any move traps the opponent (every reply left for them would finish the board), and falls back to the full exact-solved best move if none does.

Streaks shares its Skill ceiling score with Hourglass, and for a related reason: both are exactly solved in this project, but neither collapses into a formula a person just memorizes and moves past. Hourglass's real edge is that it's also provably fair to either seat. Streaks isn't — the exact solve shows whoever moves first has a forced win, a real, unmasked first-player advantage, not a coin flip. What keeps the skill ceiling high anyway is that reaching that forced win isn't automatic — it takes tracking parity across three arms at once, not a single quick trick to memorize.