# Comparing two ordered lists

Hi I would appreciate it if someone can point me in the right direction. I'm looking for an algorithm or mathematical theory which I would use to compute the similarity between two ordered lists, where each list element can have n sub-elements. I will explain with an example:

Suppose I go to a baseball game and I record the sequence of strikes and balls for each of the first 30 players at bat. My list looks like this, where P is a player, S is a strike and B is a ball. Order matters.

L1: {P1=(S,S,S)}, {P2=(B,B,S)}, {P3=(B,B,S,S)}, ...

My friend goes to a baseball game and does the same thing. Later, we meet up and compare our lists. We find that our lists are almost identical except that I recorded a strike for player 16 where my friend recorded a ball. What are the chances we were at the same game and one of us made a mistake at player 16?

• Thanks to both of you. Can one of you provide me with a URL to free site like wikipedia where I can read up about the methodology?
– Ergo
Commented Feb 16, 2015 at 15:13