If you don't read Basketball Prospectus, Kevin Pelton is currently going through a series of articles on free agents by position.  As of today, he's gone PG, SG, and SF.

The stats seem to put little Nate Robinson behind only Raymond Felton, Kyle Lowry, Luke Ridnour, and Jason Blake in the estimated wins above replacement player, while Robinson actually has the highest estimated win % for a team consisting of the player plus four average teammates for any of the free agent point guards.  Of Robinson, Pelton writes, "What Robinson needs is a coach who, like Mike D'Antoni in 2008-09, will focus on what he can do and how to utilize his unique skills rather than dwelling on his shortcomings."

Predictably, concern is had over the aging of Ray Allen, who the numbers have as inferior to the hated Quentin Richardson.  There's an entire paragraph on Tony Allen:

I feel like I could write an entertaining 20,000 words on the Celtics' other Allen. The relationship between him and Boston fans fascinates me, as does Allen's game. Going by the Bill Simmons Table Test, Allen brings a lot to the table on defense while also taking a lot off the table with his complete inability to shoot and horrendous decision-making. If you're willing to live with the mistakes, Allen really is a phenomenal individual defender who has historically shined in adjusted plus-minus analysis. He's better than a lot of players with stronger defensive reputations.

If nothing else, this series will help you learn the names of potential vet minimum pick-ups to speculate over, with some enjoyable snark about players you don't want to see in green.