all information is good information

Every expert game of minesweeper is the same. In all games you are trying to uncover 480 pieces of information. If you discover that information in chunks of fifty, fine. If you go from 1 to 480 one piece at a time, you still get the win.

It's important to keep this in mind because piece of information has equal value. In my experience, I'd say that one in four games can be won through logic. This means that the vast majority of the time you're going to have to make some educated guesses, or worst case scenario, shots in the dark. When you get to a point where you'll need to make such a move, you want to have figured out every single piece of information you can logically have arrived at. A good way to think about it is that a click that uncovers only a single piece of information is still better than a click that you can't know the result of.

Today's video is done without the shift key which lead to a rare misclick, see if you can spot it! In addition, the last three mines were not arrived at through logic. As near as I can tell there are two possible configurations. I just took a shot and it ended up being right.

the one sammich and changing to rye bread

Today we're going to talk about another common pattern as well as an important critical thinking skill. First up the pattern, this is known colloquially as the one sammich, let's examine:

As you can tell the one sammich is when you have one, two, one in a row. The one sammich will typically yield five pieces of information (for future reference, a piece of information is one known square).

Shown are the three possible places for the twos mines, but which two are correct?

This doesn't work because there are now two mines in the one squares outskirts. If we shift those two mines to the right, then it doesn't work because there are two mines in the other ones outskirts.

This will always be the solution to the one sammich. Unlike the three corner, there are only three possible mine layouts and only this one works.

Highlighted are the five pieces of information that you are typically guaranteed from the one sammich. Here you got quite a bit more information. The two twos to the lower left of the left one were gained form this. In addition we were given a solved two in the middle.

An important thing when examining a board is to consider numbers not for what they're shown as, but what they functionally are. The following scenario uses a one sammich to highlight this.

This might not look like a one sammich, but make no mistake, it's identical to the above scenario.

You see, because the two already has a mine touching it, it's functionally just a one as shown here.

That makes this the correct solution.

Once again, we get five pieces of information. This solution gives another solved two for even more information!

As always, here's a minesweeper game won through logic, today set to wesley willis, cause, you know, heinz is america's favorite ketchup

The three corner

Probably the most important skill in minesweeper is pattern recognition. There are a finite number of scenarios that can arise during a game and memorizing some of the more common ones allows for speedier play. Today's example is known colloquially as the three corner.

The three corner is, as you may have guessed, when you have a three on a corner flanked by two ones. Every three corner provides you with three pieces of information.

Shown are the five possible mine places for the three, of course only three of them are relevant, but which ones?

In this scenario, the three places would not work as it has two bombs touching the upper left one. If we rotate that line ninety degrees, we reach the same problem with the lower right one. This tells us that there can never be more than two bombs on a side. So one bomb on each side and then the third one has to go on the actual corner.

The corner bomb will always be there. The question marks show the possible places for the other two, but as discussed above we know that each linear set of question marks can contain only one bomb (note: pro minesweepers never use the question mark). No matter where the bomb is placed on the side, it will provide the bomb for the one in the three corner. This is how we get our three pieces of information.

1. We know a bomb is in the corner

2. We know the upper left one has a known space on the outside

3. We know the lower right one has a known space on the outside

We close today with an example of a minesweeper game won only through logic (after the initial press of course) set to the beatles for some reason.