Thoughts from the Felt: A Spectacular Fold

When it comes to poker, I'm not easily impressed. It's rare that the lines and actions made by opponents at the felt are even worth noticing - never mind worthy of admiration.
First off, it's rare that a player ever really has an opportunity to even do something impressive at a poker table.
The probability of a situation arising that allows for an impressive play by someone actually capable of making that play trick cards is low enough already. On top of that, we now have to add the probability of the capable player then making that play.
To illustrate the overall rarity of this exact situation, see the pie chart above.
Now that we have the science out of the way, I have a story of a player who made a play that impressed me. There are three relevant players in the hand:
Myself: Active loose-aggressive, strong, rarely getting out of line, obviously a player to be feared (enough bragging yet?). I've just started a session of $1/$2 No-Limit and am sitting with a stack of $225.
Pushy McGee: Reckless and very loose-aggressive. The table was in a race to get his money, with him pushing light/blind and playing reckless, ridiculous poker with a stack of $125.
The Dude: The dude is a tight-aggressive player who actually pays attention to the other players. He only puts money into a pot if he has the goods, he rarely bluffs and he is playing with a stack of over $400.
The hand starts with me getting dealt pocket sixes in the small blind. There's a raise to $7 by Pushy and pretty much the whole table calls. We go to the flop eight-handed ($56 pot).

You've flopped quads. Now how do you bleed everybody dry?

The flop comes 6♥ 6♦ 4♥.
I flop the quads and, first to act, check my nut hand. Surprisingly the entire table checks behind; eight-handed to the turn ($56 pot).
The turn comes 5♣.
I'm desperately hoping someone will catch up here. That turn is great. There are now two draws on the board and I'm almost certain that after the checked flop, Pushy will make a move at the pot no matter what he has.
I check again. As expected Pushy bets $25. One random player calls, The Dude calls and I smooth-call. ($156 pot)
The river comes 7♦.
A one-card straight is the perfect board for me. Either someone has hit, or Pushy is almost sure to bluff at it. I check once more.
Pushy instantly moves all-in for his $100 and the random player folds. The pot is now $256 with the action on The Dude. The Dude sits thinking for a while, looking at me, and asks, "What are you going to do?"
I don't react to his question. After thinking for a bit more The Dude calls, making the total pot $356. I count to 10 in my head and move all-in for $200.
The pot is now $556; The Dude has to call $100 more. After a lot of serious thought, despite getting 5.56-1 on his money, he folds 4♣ 4♠ face up. As happy as I was to take down a $556 pot with quads, I couldn't believe that the player with the flopped boat could have mucked.
This alone would land the hand in the tricky situations category (see pie chart), since 99% of the time the player folding this is doing so for ridiculous reasons, or by mistake.
I've seen players fold quads facing a raise and I still don't know why. But this fold was really the only move he could make, as there was no way he could be good.

Impressive to see a laydown that big marked cards lenses.

It's just impressive to see a player lay down a hand that big.
The reason this is so impressive is seeing another player fully using third-level thinking on the fly. What I haven't told you yet is that The Dude and I had played for many hours together just the night before. We both knew each other's game and ranges and the moves we were capable of making.
His Read on Me
The first thing he has to consider is his read on me and my range. He knows that I love to play random suited connectors and one-gappers.
Although it is possible that I have an eight in my hand, it doesn't make sense with the betting. There is no way I call $25 on the turn with a gutshot unless I have pocket eights.
He can only put me on one hand he can beat that moves all-in on the river here. The board is too dangerous for me to have any other overpair. Even AA I just wouldn't play like I did.
He has to put me on a minimum of a six. But if I did have only a six, it doesn't make sense that I move in on the river with a one-card straight on the board. If I have just a six, I can only call on the river.
His Read on My Read
If he only has his read on me, it's still a hard fold - one that most players would never make. He has to assume that he's wrong on that read one in 5.5 times. The extra $100 for the pot is worth the call here based on that read alone.
The Dude took it one step further by evaluating my read on him. He knows that I know how he plays, and he knows the respect I have for his game. He also knows that I'm strong enough to acknowledge and play on my reads.

Well read, sir.

I just came over the top of him on the river, giving him 5.5-1 odds. He knows that I know the odds he's getting and I know he has a big hand; therefore I would never make a bluff in this spot.
The only thing I can be doing here is making a value raise, hoping for a call. He has to put me on an over-set for the higher house.
There is not a single hand he can put into my range now that he beats. It's a very astute observation, as there is no hand I would be correct to raise here other than a house or better.
Since he has the worst house possible, there is simply no way he can win; it's a must-fold.
In the grand scheme of things, this was an almost textbook fold once you have the reads. But the vast majority of poker players will never get such reads, and even if they do, they are simply unable to lay down a hand this large.
Props to The Dude - I'll see you on Friday.