Thursday 19 August 2010

In London

After struggling on trains with the two suitcases I needed for the games and clothers I was bringing I arrived in Holborn. I had a bit of a problem as it had turned out that the automatic booking system had put in me in the wrong LSE building. Luckily, a helpful person was able to help me out at the front desk.

Only a pay-as-you-go internet at the moment but when the event starts on Saturday I should have some games to talk about.

Tuesday 17 August 2010

Chess - pawn structure

Once again, I am simply going to be using the Guradian Newspaper article as my inspiration today.

http://www.guardian.co.uk/sport/2010/aug/17/luke-mcshane-chess

In its printed form what I found interesting is the move being described as surprising was that it was the move that I jumped to first. Either this means that I am bad at looking for the normal moves or the shape of this position is such that the move should not be surprising.

But what I think is instructive about the position - is if you look at blacks possible Knight moves.

Nc5
Ng8
or
Nf7

all other Knight moves the Knight can simply be taken.

Now look at Ng3. Black's own pawns mean that the only move that the Kinght can make is back to the square it came.

If you look at the squares where Black can break through the pawn line: a4, a5 or breaking through on to g4.

This takes several moves and white can be progressing all the time. This makes White's black bishop seem very powerful.

The thing that you see in GM chess is how difficult it is to pass their pawns. Both players find themselves blockaded in. In this instance the only real way out for Black was the line mentioned in the article. But the idea of giving black a break through is unattractive.

If it wasn't for the exposure of the White King it would be even more clear cut.

Monday 16 August 2010

Poker - flopping a straight

I have just finished setting the Mastermind for the decamenathlon (http://www.boardability.com/game.php?id=decamentathlon ). So I probably shouldn't discuss any mastermind until after the paper is sat

So back to my discussions about poker. In the Amateur World Poker Championships 2002 I had a hand that relates back to the Victoria Coren hand in my last blog.

In pot limit Texas Hold'em.
I made what may not have been the wisest of raises early on in the tournament.
I had KQ of hearts.

I raised pot - the blinds folded and I got two callers.

The flop comes: Jack of Diamonds, 10 of Diamonds and Ace of Spades.
So on the AJT flop that I call the "flop of death" I have flopped the nuts.

My right-hand opponent checks, I build the pot by again betting the maximum. Left-hand opponent re-raises!

At this point I now just want to take the hand down. It is early in the tournament and to win the chips in front of me will give me a good cushion. The two diamonds on the board look ugly. So I telegraph my hand, not playing particularly well, I reraise to pot.

 I realise to my chagrin that had forgotten to wait for LHO to fold. I had read that they had nothing but...

Now my RHO who I have played against before calls. At this point he now knows I am in front.

The problem with straights are that they can never get better. If the board pairs or a three flush comes you may well be completely out of the hand. Now, comes the turn:

Ace of Diamonds. This is the worst card that I could have seen. Now my opponent who is not placing me the straight has at least two pairs and a diamond and probably has already a flush.

I make a feeler bet and predictably RHO now can make a bet for his remaining chips, now I have about half my stack left at this point.
Do I call?
I reluctantly decide to fold thinking that I will still have chances later.
But this is where I make my big mistake. I have made the pot big and any other player at the table would have never put down the straight. I wanted to know if I had made the right decision but I was left in a position where I had no way of knowing.

With this mindset I should have pushed my chips in at least then I would have known that I made a bad decision.
What ended up happening was that I was disciplined enough not to let the table know what I had done at first but then in two hands time I was talking about the decision I made.
Never - let people know what you are capabale of folding.
I was knocked out without getting another hand. I even had a restless night's sleep.

What I did manage to do though was learn that you have to play poker and never have to know what your opponent's cards are. you have to be prepared to fold a hand that is in front once in a while if you are going to play tournament poker. You just need to make sure that you get some benefit from your action.

Thursday 12 August 2010

Folding a big hand in poker

Victoria Coren's article Yesterday in the guardian recounts how she had the shoe straight and folded.

http://www.guardian.co.uk/sport/2010/aug/11/victoria-coren-poker

The point of the article is that not knowing if she did the right thing still haunts her. Now to be a good poker player you have to occasionally fold a big hand. With large televised events there is the chance that you will find out if you did the right thing as you might get to see your opponents cards.

You could try asking - but this will rarely get the response that you wanted. So how should you handle these situations?

The problem is that she has disguised her hand. This is a good thing but it makes it very difficult to read your opponent. They think that they have the better hand and this is shown by their body language. At best you might see that they are unsure.

Now you are in a position where your opponent is unlikely to fold to further raises and you don't want to be involved in the hand due to the range of hands you put your opponent on. So you decide to fold. This is the critical moment, you should now act as if you had been bluffing with nothing.

This helps for two reasons:
1) it makes it more difficult for people to read you
2) It puts you in a better frame of mind for folding

The problem is if you show a fantastic fold the players who are not good enough to beat you will think that you are showing weakness. You will then be bullied by the other stacks.

I will come back to this hand shortly and give the example of mine that was very similar to this, that I didn't handle well.

A final note is if at the point of the flop the other player has flopped a set then they win with any pair.

With 876 this leaves 7 outs on the turn and a further 10 on the river ~38% but the danger hand was the
10 9.

It took a while

I was sure that there was going to be a solution to the all-play-all movement somewhere in the computer science literature. However, there doesn't appear to be any direct work done to solving the problem.

There are a few timetabling problems that relate and it could well be like the Travelling Salesman problem unless you know its name it is difficult to find.

Anyway, since I was probably only going to need small numbers I decided that I would just settle for a simple computer program.

To find the possible combinations without overlaps for 3 players a round wtite down all of the numbers in combinations of pairs to form a triangle

e.g.

12
13  23
14  24  34
15  25  35  45
....

Then to find a combination you just make an L or triangle with three points and cross them out. With four players you will have 6 to cross out. Not solved the problem for diplomacy a 7 player games.

Unfortunately, the elegance of the 9 players 3 at table is not repeated for larger numbers
ie
123  456  789
168  249  357
147  258  369
159  267  348

Monday 9 August 2010

Multiplayer game movements

Hmm,
   This looks trickier than I wanted.

Pairing opponents in a two player game like chess is relatively easy.

For more than two players or team at one game is much trickier...

With a large field a complete Swiss could be run with the winners play other winners.

The 4^n means that it is unlikely that even a 5 round event would be needed to find the winner. So if you have around 30 players for a 4 player game with 5 rounds how do you find the movement. It Becomes more complicted if you have late arrivals too.

I looked-up bridge individuals and was struggling to find the solution. I thought that there would be a simple mathematical formula but I have not yet found. I will investigate further and hopefully post  a solution back here.

The objectives should be that players play against the same players as few times as possible. That each possible postion 1st /  North  should be held equally.


1 - 2 - 3 -4  has 24 configurations but it is just the grouping that is of importance to us for now.

so for 30 players we would have:
 30! / (26! 4!)
possible tables.
27405 tables = 3915 rounds

Sunday 8 August 2010

Chess - could you play like a grandmaster?

I came across the chess game recently, many of you will have seen it before:

There are some moves that a chess grandmaster plays that just would never occur to me. See if you do any better in finding GM Keith Arkell's move:

1. Nf3 Nf6 2. c4 e6


3. Nc3 d5 4. cxd5 exd5

5. d4 c6 6. Bg5 Be7

7. Qc2 g6 8. e3 Bf5

9. Bd3 Bxd3 10. Qxd3 Nbd7

11. Bh6 Bd6 12. Bg7 Rg8

13. Bxf6 Nxf6 14. O-O Qe7

15. a3 Ne4 16. b4 a6

17. Rfe1 f5 18. g3 g5

19. Nd2 g4 20. Ne2 h5

21. Nf4 h4 22. Nxe4 fxe4


White to play?

There is a link that can be found here:
http://www.chessvideos.tv/chess-game-replayer.php?id=32496
 
Now did you find his move? I would never have thought of playing it ;)