I count these correct guesses:
Anibal Sanchez - Tigers*
Hiroki Kuroda - Yankees*
Angel Pagan - Giants*
David Ortiz - Red Sox*
Adam LaRoche - Nationals*
Marco Scutaro - Giants*
Stephen Drew - Red Sox
Ryan Ludwick - Reds*
A.J. Pierzynski - Rangers
Mariano Rivera - Yankees*
Mike Adams - Phillies
Andy Pettitte - Yankees*
Jeremy Affeldt - Giants*
So they correctly guessed that *10 guys would return to their previous teams. But I think the Drew, Pierzynski, and Adams guesses deserve some respect.
Still not a great record. But getting Stephen Drew is pretty cool.