Chordy

In the League, that move is called a chord. Chordy is its greatest champion. He is also, and this is the important part, its most careful one.

A young duckling came waddling up to the pond one breezy afternoon, flustered and a bit teary. "Everyone keeps telling me to chord," she said, shaking out her damp feathers. "They say it's the fast way. But I tried it, and I hit a mine straight away and lost the whole board. I don't understand what I did wrong."

Chordy's eye-stalks swivelled toward her with kind, focused interest. "Show me the board where it happened," he said. "Right where it went wrong."

She showed him. Chordy scuttled sideways across the tiles, the way crabs do, until he reached a number three sitting in the middle of a cluster of hidden squares, with three small red flags planted around it.

"Here's how a chord works," he said. "This three tells you that exactly three mines touch it. Now, suppose you've already found all three of those mines and flagged them. Then every other hidden square around the three has to be safe. There's no room left for another mine. The number has used up its whole count. So instead of clicking each of those safe squares one at a time, you click on the three itself. And every one of its other neighbors opens at once."

He spread his claws in a wide ring around the number. "Pinch! One click instead of five. That's how the very best players get their efficiency score above one: a single chord can do the work of several ordinary clicks. Clicksy the cricket loves it when players chord well."

"Then why did mine go so wrong?" asked the duckling.

Chordy lowered his eye-stalks until they were nearly touching her flags, and he studied them for a long, silent moment. Then he pointed one claw, very gently, at a single flag on the left.

"This one," he said quietly. "Was it proven? Did a number actually force it to be a mine?"

The duckling hesitated, her bill trembling a little. "I... thought it looked like a mine. It seemed like a mine-ish sort of place."

"Ah," said Chordy softly, and there was no scolding anywhere in it. "That's the one and only danger in a chord. A chord trusts your flags completely. It doesn't double-check them. It can't. It just takes your word that every flag is on a real mine, and then it opens everything else. So if every flag really is on a mine, the chord is perfectly safe. But if even one flag is in the wrong spot, then the real mine is still hidden somewhere in that ring. And when you chord, you open it."

The duckling's feathers drooped. "So the chord didn't make the mistake," she said slowly. "My flag did. The chord just carried out my mistake very efficiently."

"Exactly right," said Chordy, and he gave her the gentlest tap with the smooth flat side of his claw. "And do you see why that's actually good news? It means chording itself isn't dangerous at all. Guessing flags is. If you only ever flag mines that you've proven, the way Surefoot the goat does, then every single chord you make will be safe. The big fast move is only ever as good as the small careful steps underneath it. Get the small steps right, and the big move takes care of itself."

He showed her how to check each flag first. Find the number that proved it. Make sure the count truly forced it, that there was no other way the mines could fit. Only then, once every flag around the three was certain and not just likely, did she reach out and click the number.