A Small Warning Regarding Hibernate

I found the following quote that struck a chord with me.

The problem is sort of cultural. Some developers come to using a tool like Hibernate because they are uncomfortable with SQL and with relational databases. We would say that this is exactly the wrong reason to use Hibernate. You should be very comfortable with SQL and JDBC before you start using Hibernate - Hibernate builds on JDBC, it does not replace it.

ref. http://www.javaperformancetuning.com/news/interview041.shtml

The Martingale System of Gambling

Just a small exercise for my edification, regarding the "Gamblers Fallacy" inherent to "The Martingale" system of gambling.

import java.util.*;
import java.io.*;
import java.text.*;

/**
 * A quick implementation of the Martingale
 * system of gambling. Run it, and it will
 * play at the roulette table, until broke.
 * How far can you make it before going
 * broke? Let me know!
 */
public class Martingale
{    

  
  public static String padLeftToTotal(long s, long n) {
    return String.format("%1$#" + (n-(s+"").length()) + 
      "s", s + "");  
  }

  public static void main(String[] stuff)
  {
    long account = 255;
    long bet = 1;
    long maxbet = 0;
    
    // 0..36
    // where red: 1, 3, 5, 7, .. 36
    // where black: 2, 4, 6, .. 35
    // where green : 0
    while (account > 0L)
    {
      long result = 
        Math.round(Math.random()*36.0);
      System.out.println("Account: " + 
        padLeftToTotal(account, 15) + 
        " Betting " + padLeftToTotal(bet, 15) + 
        " $ on red.. result is " + 
        padLeftToTotal(result, 3) + " " + 
        (result == 0 ? "green" : ((result % 2) == 0 ? "black" : "  red")));
      if (result != 0 && (result % 2) == 1)
      {
        // red, we win!
        account += bet;
        bet = 1;
      }
      else
      {
        // not red, we lose!
        account -= bet;
        bet *= 2;
        if (bet > maxbet) 
        {
          maxbet = bet;
          System.out.println("Maximum bet increased to " + maxbet + "$");
          try
          {
            Thread.sleep(1000);
          } catch (Exception e)
          {
          }
        }
      }
    }
    System.out.println("You lose, dude!");
    System.out.println("You now owe the casino " + 
      (-account) + " $");
  }

}

“Remember this well, Lady Luck has no memory.”

References

Wikipedia : Gambler's Fallacy

http://en.wikipedia.org/wiki/Gambler%27s_fallacy

What happened at Monte Carlo in 1913?

http://www.fallacyfiles.org/gamblers.html

Update: 10 February 2015, added Monte Carlo link.