Below are two different lines. Take some time looking at the differences between them and then post what you think they both represent in the comments section. I'll be back tomorrow to fill in the details (unless someone gets it before then).
Update [2007-10-31 12:52:9 by David Cohen]:It only took an hour for Seth to get the answer in the comments below. The chart compares the stats for Phillies thirdbasemen since Scott Rolen was traded on July 29, 2002, with Alex Rodriguez's stats for the same period. Draw your own conclusions.