My favorite explanation of this effect goes like this: You have students in a classroom, sitting in 5 rows of 5 students. The teacher gives each student a crump

My favorite explanation of this effect goes like this: You have students in a classroom, sitting in 5 rows of 5 students. The teacher gives each student a crumpled ball of paper. Each ball is identical. The teacher then places a bin at the very front of the class and says "Okay, you each get one throw from your seat. If you hit the bin, you get an A" Equal opportunity. Everyone is throwing the same ball into the same bin, and everyone gets a chance to throw their ball of paper, hit the bin, and get an A. But some students are 5ft away and others are 30ft away. Suddenly not so fair. This comic also explains it well: http://imgur.com/gallery/h82vC http://imgur.com/gallery/h82vC