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Take the 25 Intellectuals (or any other group of 25 people) that participate in the Intellectuals Chess Tournament, promoted by Cavatine. What is the probability that at least two of them were born in the same day and month (forget the year of birth)? Go, Intellectuals !

Have fun my dear intellectual chess friends! Mind Reading Have someone pick a number between 1 and 9. Have someone pick a number between 1 and 9. Now have him use a calculator to first multiply it by 9, and then multiply it by 12,345,679 (notice there is no 8 in that number.). Have the person show you the result so you can tell him the original number he selected. How? If he selected 5, the final answer is 555,555,555. If he selected 3, the final answer is 333,333,333. The reason: 9 x 12345679 = 111111111. You multiplied your digit by 111111111. (By the way, that 8-digit number (12,345,679) is easily memorized: only the 8 is missing from the sequence.) The 421 Loop Pick a whole number and enter it into your calculator. If it is even, divide by 2. If it is odd, multiply by 3 and add 1. Repeat the process with the new number over and over. What happens? The sequence always ends in the "loop": 4.....2.....1.....4.....2.....1... Example: Start with 13. 13 is odd, so we multiply by 3 and add 1. We get 40. (\(13 \times 3 = 39 + 1= 40\)) 40 is even, so we divide by 2. We get 20. (\(40 \div 2 = 20\)) 20 is even, so we divide by 2 and get 10. 10 is also even so we divide by 2 again and get 5. 5 is odd so we multiply by 3 and add 1. We get 16. 16 is even, so we divide by 2 and get 8. 8 is also even so we divide by 2 again and get 4. 4 is even so we divide by 2. We get 2. 2 is even, so we divide by 1 and get 1. 1 is odd, so we multiply by 3 and add 1. We get 4. 4 is even so we divide by 2. We get 2. And so we begin the loop 4.....2.....1.....4.....2.....1... Have someone secretly select a three-digit number and enter it twice into her calculator. (For example: 123123) Have her concentrate on the display. You will try to discern her thoughts. From across the room (or over the phone), announce that the number is divisible by 11. Have her verify it by dividing by 11. Announce that the result is also divisible by 13. Have her verify it. Have him divide by his original three-digit number. Announce that the final answer is 7. You can use this to predict Good Luck for him. If you wish to predict Bad Luck, have him divide by 7 in step 3; the final answer will be 13. Why does this work? Entering a three-digit number twice (123123) is equivalent to multiplying it by 1001. (\(123 \times 1001 = 123,123\)). Since \(1001 = 7 \times 11 \times 13\), the six-digit number will be divisible by 7, 11, 13, and the original three-digit number. The Secret of 73 For this trick, secretly write 73 on a piece of paper, fold it up, and give to an unsuspecting friend. Now have your friend select a four-digit number and enter it twice into a calculator. (For example: 12341234) Announce that the number is divisible by 137 and have him verify it on his calculator. Next, announce that he can now divide by his original four-digit number. After he has done so, dramatically command him to look at your prediction on the paper. It will match his calculator display: 73 Why does this work? Entering a three-digit number twice (12341234) is equivalent to multiplying it by 10001. (\(1234 \times 10001 = 12341234\)). Since \(10001 = 73 \times 137\), the eight-digit number will be divisible by 73, 137, and the original four-digit number. The 6174 loop Select a four-digit number. (Do not use 1111, 2222, etc.) Arrange the digits in increasing order. Arrange the digits in decreasing order. Subtract the smaller number from the larger number. Repeat steps 2, 3, and 4 with the result, and so on. What happens? Let's try 7173 Arrange the digits in increasing order. 1377 Arrange the digits in decreasing order. 7731 Subtract the smaller number from the larger number. 7731 - 1377 = 6354 Repeat the process with 6354 6543 - 3456 = 3087 8730 - 0378 = 8352 8532 - 2358 = 6174 7641 - 1467 = 6174 7641 - 1467 = 6174 7641 - 1467 = 6174 (we're in a loop.) Amazingly, all four-digit numbers (not multiples of 1111) end up in the 6174-loop.

This image shows 3,000 line segments. For each i=1,2,3,…,3000 the endpoints of the i-th line segment are: (sin(34πi/3000), (1/2)cos(6πi/3000)) and ((1/2)sin(6πi/3000), cos(34πi/3000)): The next was created using ((sin(20πi/3000))3, (cos(18πi/3000))3) and ((sin(16πi/3000))3, (cos(14πi/3000))3): And the final fishlike image was created with 1,000 line segments with endpoints (2sin((4πi/1000)+(π/6)), (1/2)sin((6πi/1000)+(3π/2))) and (sin((10πi/1000)+(π/2)), sin((6πi/1000)+(π/3))):

Just want to hear you, guys.. Abraços.

Do you good people ever play Tactics Trainer puzzles here on chess.com ? http://www.chess.com/tactics/ For most people it is a good tool to help you improve. If you are a free membership person you can play 3 TT puzzles every day. If you are a Gold member, you get 25 per day and if you are Platinum or Diamond you can play unlimited number of puzzles per day. I usually play about 8 - 15 a day. About a year ago I got kinda crazy with it and was playing 30-40 a day. It is a lot of fun, but be warned - if you play as rated (where every one affects your TT score) you can lost points for being too slow even if you get it right. When chess.com goes to V3 they are going to change it so that you don't lost points if you get it right even if your are slow, but for now you have to suffer through that. Any commnets? Any big-time TT players here? I can tell lots of TT stories if anyone cares... Rocky

OK, here's the deal. Let's talk about one of my 3 favorite things, food. We have people from all over the world in this group. Let's talk about the typical food that you eat in a day. I will talk about Saturday. I get up and get a cup of coffee to get woke up after one cup I will put some (bought frozen at the store) biscuits in the oven and fry some bacon on the stove. After I cook the bacon I fix two eggs, either scrampled or fried. So it is coffee, bacon, eggs, and biscuits for breakfast. Lunch (sometimes called dinner) is typically lighter than dinner. I will have a ham sandwich and potato chips for lunch, or maybe a hamburger and fries. For dinner, (sometimes called supper) it varies quie a bit. Let's go with this. Fried chicken and mashed potatoes and green beans followed by a piece of apple pie. Now people from other coutries (or you other Yankees) - what say you about typical food?

I was wandering if anyone has created a chess opening and would you be willing to critique anyones if your have. I am going to share 3 that I created. The first is called gevurah ( strength or power) e5,g6,Bg7,Ne7,d6,Be6,Nc6,0-0 Second is Chesed (Mercy) d5,b6,Bb7,e6,Nc6,Nf6,Qe7 Third is Gehen'nas Gate (spin on the Kings Indian Attack) e4,d3,a3,Be3,g3,Bg2,Nf3,Nd2,ke2 or Qe2,0-0 Gehen'nas Peak (second Variation) e4,a3,Bc4,Ba2,d3,h3,Bf4,Bh2,Nf3,Nd2,Qe2,c3,0-0

The objective of this topic is to hear from group people why they play chess. You can play some sports for physical reasons, gamble to win money. Why do you play chess? What do you get by playing chess? Abraços.

Where did your username originate? There are many unique, odd, or even downright ludicrous usernames on this site. Some have an obvious reason, some are chess-related, some are personal, some look like they were created when the user faceplanted into his keyboard, and et cetera. Shall we discuss where ours originated? I'll start. My username, camberfoil, is a combination of the words camber, and foil, short for airfoil. Camber refers to the asymmetry of the upper and lower halves of a plane's airfoil (that's where the foil part comes in). This asymmetry creates a differential in pressure over and below the wing as the aircraft accelerates. Once the speed is sufficient, the pressure differential will grow enough so that the wing is drawn to the area of low pressure, above it, pulling the wing upwards, producing lift. It is, in essence, how a plane flies. Plus I just like saying camber over and over again. Camber. CAM-BER. Camber. Cam-BER. CAM-ber. Caaaaammmm-berrrrrrr. I think I've gone off the deep end.

I came up with an idea for how to teach higher animals, especially cats, dogs, birds, and apes, how to play a simplified form of chess. The main idea is that you create an apparatus large enough that relates to the animal in a physical way, rather than expect the animal to take an interest in some tiny, flat, 8x8 grid that is probably irrelevant to the main goals in its life (eating, sleeping, sex, exercise, play, etc.). For example, you create a small but nice area for a dog to sleep in the middle of that area, except there are two "lanes" on each side of it that look like bowling lanes that come from a fenced off area of equal size, and each lane slowly sends down some small but annoying bowling ball-like apparatus to where the dog sleeps, maybe with a lot of noise, or puffing air, or bad odor, enough to disturb the dog when it's sleeping. The dog must learn on its own that if it places a similar bowling ball in the lane before the offending bowling ball arrives, that the outgoing ball with collide with the incoming ball and nullify it. The dog then learns the basic concept of rooks contesting an open file. Similarly, while the dog is sleeping, the low ceiling could start to have protruberances that descend, making it annoying for the dog to move around in its bed. The dog must learn on its own that by shifting pedestals over to underneath where the protruberances are descending, that the pedestals will halt the protruberances from descending further. This is like pawns coming head to head with enemy pawns, unable to advance. Such ideas could be extended to all basic chess moves. Maybe a human could be present to give examples to the dog of how a threat can be nullified. Dogs learn fairly quickly, so a dog could probably learn to make those counter moves after just a few observations. I'm not suggesting that animals could see beyond 2-ply moves like those, but you never know. It would be interesting to see what happened, and it would be interesting to figure out how to make analogs in real life to the pieces and motions that exist on a chess board.

I asked a question what's the meaning of life? Now my answer would be to live, learn, procreate and pass on the knowledge you learned in this life to the next life, through your cells which I might add records information from all throughout your life and stores them in the cells ( this has been proven as our DNA still has information from our ancient ancestors down to the first human considering it has been proven that we all have a common anscestor regardless of the superficial race,nationality that we have created in order to classify ourselves). Now the question is, if we were able to unlock the full potential of our brains and be able to access this information would it make use no longer human?

F]The Squares of the City John Brunner - PDF Archive

Considering ratings in: blitz live, standard live and online (correspondence) chess is it reasonable to admit that for a regular player the online rating shoul be the highest of the three? And that blitz live the smallest? Abraços.

I've been following the Anand vs. Carlsen match quite a bit now, and while there have been interesting games, the match as a whole somehow has failed to exite me as much as I had hoped. What are your impressions ? Let's talk about this match, impressions, games, analysis, psychology or whatever else you guys want to discuss about it. Maybe some fresh views will finally get me a bit more exited about it .

It would be interesting to get acquainted with GM's blunders. That would make me feel a little better.. What do you guys think?

Wired just issued an interesting article that discusses the effects of chess on the brain. http://www.wired.com/2014/10/beware-playing-lots-chess-will-shrink-brain/ .....discuss.

I've recently started studying Go. It's a really interesting game, and I've read that Emmanuel Lasker was a fan of this game. From a mathematical and computational stand point, the number of possible games on a 19x19 grid are about 10^761. The number of atoms in the universe is about 10^80. Go shares some similarities with chess in that in Go you can make sacrifices to better your position and create a capture. You can not repeat a position forever if the result is just an eternal capture and recapture by your opponent, which in Japenese is calld Ko, which means eternity. This is similar to the three move repetition rule in chess. If you want to take a break from chess, but still want to play a really challenging strategy game, check out Go. By the way, Go has professional tournaments and players, just like chess.

This thread is specifically devoted to discussing other intellectual topics besides chess.