Whenever I've tried to research Benitez's career, I've often been frustrated by the lack of complete and accurate information available. In order to judge his career (and that of any other manager) fairly, complete statistics are necessary.
I have exhaustively compiled stats for Benitez's entire career, i.e. every single competitive game, from Valladolid in 1995, through Valencia; Liverpool in the Premier League, all the way up to the Spaniard's last job at Inter Milan. I obtained these figures from reputable sources both on and offline, including the clubs themselves (when I couldn't find the information I needed).
I draw no conclusions; I'm just providing the figures for information purposes.
TABLE 1: CAREER OVERVIEW
TABLE 2 - GRAND TOTALS