One notable absence from the list of the top rush defenses as measured by RYA over its last three games is the Baltimore Ravens. After allowing 186 rushing yards in the three games prior to the New York Giants game, the Ravens rush defense allowed 207. This one game almost doubled the team's average RYA and pushed them out of the top ten.
I do not believe their rush defenses is no longer elite. As a matter of fact, I feel for whomever is rushing the ball for the Philadelphia Eagles, whether that is Brian Westbrook or Correl Buckhalter. The Ravens' defense will be looking for blood, and I wouldn't start any Eagles' RB - even if Brian Westbrook was "healthy" and playing.
Another interesting "sit question" is Chris Johnson of the Tennessee Titans. He faces a New York Jets' rush defense that ranks 6th and has consistently ranked in the top 10 during the 2008 season. Combine that with the Titans' recent explosion in the passing game and the consideration that Johnson has now played the equivalent of a full college season, and one can easily consider sitting Johnson.
To abet this decision, there are likely RBs in the pool with very favorable match-ups like Peyton Hillis in Denver facing the Raiders, Tampa Bay's Warrick Dunn against the Lions, and Derek Ward of the Giants facing Arizona. Yes, I have concluded the Giants' excellent run-blocking overcomes any rush defense stat.
Top Ten Rush Defenses: