My father had firm ideas about how you behave at a board, and every one of them works just as well with a stranger in Copenhagen at two in the morning.

1. Say hello. A "hi" when the match starts, a "gl" (good luck) if you like. It costs nothing.

2. Say "gg" at the end. Good game. Win or lose. Especially lose.

3. Don't drop. When you're losing badly, there is a temptation to close the window and walk away. FIBS will save the match, and the other player will be left waiting for you to come back and finish it, and you won't. It's called dropping, and it is the worst thing you can do on the server. People keep lists of droppers and share them. If you have to leave, say so, and offer to finish later. Real emergencies happen and people understand. A gammon coming isn't an emergency.

4. Move along. Think about the hard ones, of course. But don't take a full minute over an obvious move, and if you need to step away, tell your opponent first.

5. Don't complain about the dice. Everyone on FIBS is convinced the dice are against them. They are against everyone equally. Daddy's rule: you may say "nice roll" to your opponent. You may not say anything else about his rolls.

6. Watching. You can watch other people's matches, which is one of the best ways to learn. If you say something while watching, whisper goes only to the other watchers. kibitz goes to the players too. Don't kibitz advice into a match you're watching. The players didn't ask.

7. Turn off ready when you're not. If your status says you're ready to play, people will invite you. If you've gone to make tea, toggle ready first.

By their FIBS names, which is all I know most of them by.

Marguerite  A grandmother in Lyon, she tells me, rated around 1850. We've played fourteen matches since 1997. I have won three. She plays very fast, never says a word except "bonjour" and "gg," and takes doubles I would never take and wins them. I would cross an ocean to watch her play a back game on a real board.

Kittyhawk  A retired airline pilot in New Zealand. My two in the morning is his six in the evening, so we've become regulars. He talks about his garden, I talk about my grandchildren, and somewhere in there we play an eleven-point match. He is the one who finally explained the take point to me in a way I understood, by comparing it to a mortgage. I'm a banker. It worked.

doubleD  I believe he was about fifteen. He doubled on his first roll of every game, every game, for an entire nine-point match. I took every one. He was very surprised how that went.

pipcount  A gentleman who announced both pip counts by kibitz after every single roll, for both of us, whether we wanted them or not, for a whole seven-point match. He was always right. I have tried to think of this as a service.

Sven  The slowest player I have ever met. A five-point match took two hours and forty minutes. Every move, even the forced ones, took a minute. I was going to complain, and then at the end he wrote that he was learning English and backgammon at the same time and was reading every message twice. I play him whenever he asks.

The one I won't name  Led me 6 to 2 in a seven-point match, then I rolled three sets of doubles in a row, and he dropped. That match has been sitting in my saved games since March. Some nights I look to see if he's on. He's on. He just never finishes.

Jellyfish is a backgammon program from Norway, and it is the reason the game is changing faster now than it has in my lifetime. Nobody taught it how to play. It's what they call a neural network: it started knowing only the rules and taught itself by playing an enormous number of games against itself, keeping what worked. It now plays better than almost anyone on FIBS.

The strongest players use it to check their games after they've played them, and it has turned some of the old ideas upside down. Some opening moves that the books called mistakes, it plays happily, and the books are being rewritten. Some positions everybody passed for years, it takes. My nephew asked if that takes the fun out of it. I told him it's the other way around. For forty years I wondered whether Daddy was right about some of his crazy takes. Now there's something that can tell me. Quite a few times, he was.

I don't own Jellyfish. A friend from FIBS runs my worst matches through it for me now and then and e-mails me what it thinks. It's humbling. It's also the most useful thing anyone has ever done for my game.

Every match I play, the walnut board is open on the desk beside the monitor, set up in the starting position. It's not for anything. It's just there. When I log off at two in the morning, I put the checkers back in their felt bag the way Daddy did, white first, then red, and close the case. Then I go to bed.