Seven diamonds left, and one of them beat me

The queen of diamonds came on the river and made me the best flush in the deck.

He moved all in. I called, because of course I called, and he turned over the king and the ten of diamonds. The queen that had just made my hand had made him a straight flush, nine to king, on the same card.

This looks like the sort of hand there is nothing to learn from. That is exactly the sort of hand where the lesson hides, so I did the arithmetic on it afterwards, and there was more in there than I expected.

Seven diamonds

Count what was left in the deck on the turn. Thirteen diamonds exist. I had the ace. He had the king and the ten. The board had the four, the nine and the jack. Six accounted for, seven still out there:

2♦ 3♦ 5♦ 6♦ 7♦ 8♦ Q♦

Six of those give me an ace-high flush and the pot. He has a king-high flush in every single one of them, which means in six cases out of seven he is the one paying me off.

The seventh is the queen.

Could I have folded?

No, and it is not close.

On that final board, holding the ace of diamonds, exactly two holdings in the deck beat me: the ten and king of diamonds, and the ten and eight of diamonds. Two combinations out of the 990 he could have been dealt. Both of them need the ten of diamonds, which is the one card in the deck that turns a board full of diamonds into a board full of straight flushes.

Everything else loses to me. Every worse flush, every straight, every set, every two pair, every bluff. Fold the ace-high flush there to save yourself two combinations, and you spend the rest of the year folding to the other nine hundred and eighty-eight.

One caveat I have to make, and it is the honest kind: I do not remember the fourth board card. If it paired the board, a full house joins the list and the count goes up. But it does not change the decision, and it does not change what follows.

The decision was two streets earlier

Here is the part I could only see by counting.

On the turn I had a pair of nines and four to the nut flush, and I felt like a man in reasonable shape waiting for a good card. I was not. He had the king and ten of diamonds, and the board had three diamonds on it. Three plus two is five.

He had a flush already. I was drawing.

I could not tell you what that fourth board card was, and it turns out not to matter. There are thirty-eight cards it could have been, and I checked all of them: not one leaves me ahead on that turn. The best I ever have is trip nines, and trip nines lose to a flush.

So this was never a hand where I was winning and got hit by lightning. It was a hand where I lost the lead the moment the third diamond landed, kept drawing, and got there second.

The ace of diamonds stops you thinking

That is the actual lesson, and it is not about the river at all.

A nut flush draw feels like a draw to the nuts, because the word is right there in the name. It is not one. It is a draw to the best flush, which is a different and much smaller claim, and on a board that is three to a flush with a nine and a jack in it, the distance between those two things is a player holding the ten of diamonds.

Two things follow that are worth carrying to the table, and neither of them is "fold more":

• Three cards of one suit on board with connectivity in them means the flush is not automatically the nuts. Four of one suit on board means a straight flush needs somebody to hold one card, not two, and there are usually two cards that do it.
• The ace does not tell you where you stand, it only tells you where you stand among flushes. When the board is doing something else as well, that is a much narrower piece of information than it feels like.

What I nearly did with this hand

I nearly filed it under cooler and went to get a coffee.

The app I built has a tag for that, and I have used it plenty, and it is the right tag for this hand. But cooler is a verdict, and the trouble with writing down a verdict is that it closes the question. Six weeks later I would have read "lost nut flush to straight flush, cooler" and learned precisely nothing, because everything worth knowing about this hand happened on a street the note does not mention.

What I wrote instead was the boring version. Board went three diamonds on the turn. I treated a flush draw as a draw to the nuts. He already had the flush. River gave us both what we were looking for and his was better.

That note is worth something, because the next time a board goes three to a suit with connectivity in it, I have a hand to think about rather than a shrug. The verdict and the record are not the same object, and only one of them is any use later.

Log is free, all of it, and works offline with no account. The tags are there and they are quick, but the line underneath them is the part that pays, and it takes about fifteen seconds. Write the street where it actually went wrong, not the one where it hurt.