Corner Cato

Every point on the morris board, Cato taught, belongs to exactly two mill-lines. The corner was no exception. A corner sits on one line running along the edge and one line running along the side — two chances to be part of a closed mill, the same as almost any other point. "The corner is slow to move," Cato said, "but it is not slow to count. Fill a corner and you have advanced two of your lines at once, even if that piece never takes another step all game."

This was the subtext the older students eventually heard: that a thing can be low in mobility and still high in worth. The corner does not run. It anchors. And a network of mills is built as much on anchors as on runners.

Cato had learned the trap, though, the hard way — by loving corners too much.

"When I first understood that corners were safe and still counted for two lines, I put everything in corners," he admitted. "Nine pieces, one per angle, a tidy fortress. And I got ground to dust, because in the sliding phase my whole army could barely move. My opponent's cross-point pieces flowed around the board opening and closing mills, and my corner pieces sat there being safe and counting for two lines and doing absolutely nothing. Safety that can't act is just a slow surrender."

The right use of a corner, he explained, was as one note in a chord — a stable anchor around which mobile pieces swing. "Put an anchor in a corner. Then put a runner on a cross-point beside it. The anchor holds the line; the runner does the opening and closing. Together they make a mill that stays half-built no matter what — because the corner piece never has to leave."

The Elder tested Cato with a placement puzzle: one piece left to place, three empty points open — a corner, an edge-middle, and a cross-point — and asked which served best.

Cato didn't answer at once. "It depends what I already have," he said. "If my other pieces are all runners with no anchor, I take the corner — I need a point that holds two lines and never has to move, or my mills will keep collapsing when I slide. But if I already have anchors and I need reach, I take the cross-point, because a runner that can swing four ways is worth more than another stone that can't move." He placed his piece in the corner. "Here I've got runners and no anchor. So — the quiet spot. The one that counts for two and never flinches."

"You chose the least mobile point on the board," the Elder said.

"I chose the point my position was missing," Cato replied. "A corner isn't good or bad. It's slow and steady. The skill is knowing when slow and steady is exactly what your board needs — and when it's the thing that traps you."