Not sure, but I think too much is made of using history to project the potential of current players.
agreed. same with team records.
i would even say that too much is made of what a player has done in previous years to project their current potential. mainly thinking about a discussion i was having on another board about farve. people thought of him as being an iron man coming into this season and coming off one of the best seasons statistically of his career while i was looking at a 40 year old man who had just had the beating of his life (thanks to a douche plan by gregg williams) who was coming back to the game in massive pain. a few games into the season he hasn't played well and now he has a fractured foot. same could be said for jake last year. while many of us were noticing that there was a big time falling off in his performance, there were others who kept on looking at his whole body of work and believing that he'd overcome his struggles.
point is, it can help looking at the past but past performance is far from being a reliable indicator of current and future trends. take it with a grain of salt and don't be blind to what is going on at the time.