Whatever Shanahan’s thinking was, benching McNabb says plenty about what the Redskins think about the future of McNabb, whom they traded for in the off-season but have not signed to a contract extension for next season. McNabb responded mildly by saying, “Well, he makes the decisions,” but he is a sensitive sort. Now he — and a locker room as stunned by the decision as McNabb was — have the bye week to stew a little more.  Tony Dungy, the former Colts coach, summed it up perfectly on NBC’s broadcast Sunday night. “What you’re saying is, ‘I don’t believe in my quarterback,’ ” Dungy said. “And to me, you cannot do that unless you plan on making a quarterback change.”  Shanahan, at least, gets points for making a difficult decision. The Vikings’ Brad Childress, not so much. It was instructive to listen to Childress, who all but shrugged in resignation when asked if Favre was likely to start next Sunday against Arizona, after Favre took stitches to his chin on a hit that left him woozy. Childress might have come as close as he ever will to benching Favre last week, when Favre was hobbled by two fractures in his ankle. But even with Favre on pace for a career-worst year, Childress could not make the defining move of the season, and of his own career. Favre played and played decently in the Vikings’ loss to the Patriots.  “Let’s have a little history, let’s look a little bit back,” Childress said Sunday night. “You could probably venture, take a little guess, whether you thought he would go. I think he probably takes a swing at it next week. What do you think?”  It doesn’t mean Favre should play, though, no matter his health. Through seven games, Favre has thrown 11 interceptions, which is halfway toward the 22 he threw when he disintegrated with the Jets. His interception percentage (interceptions compared with passes thrown) is 5.2 percent, which would be the worst of his career as a starter, and his quarterback rating of 69.8 is by far the worst since he became the Green Bay starter in 1992. This is a quarterback in clear decline.  Nobody would know that by listening to Favre, though. Last week and again on Sunday, he marveled at his own recuperative powers and revealed just how much he thinks about his starting streak. Were most of the questions about him? Yes. Did he deflect any of them to talk about the Vikings as a whole? No, although he did throw out a bon mot to Tom Brady for his improvisational beauty on a 65-yard touchdown pass to Brandon Tate. But most of it involved Favre navel-gazing.  “I was shocked that I was able to play and move around the way I was,” Favre said. “My prayers were answered. I wanted the chance to play. I wanted the chance to play and play at a high-enough level to give us a chance to win. I didn’t want to play just to play. I didn’t want to come in for one play to get a start; I didn’t want to do that. I wanted to come in and help this team win. It was touch-and-go even before the game today.”  Later, he added, “I think what would keep most guys out for a long time obviously hasn’t kept me out.”  Check the results. That might not be such a good thing.  So much for the panic that the N.F.L.’s crackdown on hits to the head and neck would make defenders so cautious that scoring would soar as big plays multiplied.  In the second week of the crackdown Sunday, scoring dropped by an average of more than 10 points per game from last week — down to 41.25 points per game. That included 73 combined points scored by the Tampa Bay Buccaneers and the Arizona Cardinals, and a measly 9 by the Green Bay Packers and the Jets. That was one of only two games on Sunday that involved two teams with winning records, with the Sunday night game between the Saints and the Steelers being the other. They combined for 30 points.  Does that mean defenders reverted to their old ways? Not exactly. There were two penalties for impermissible hits to the head Sunday, by Jacksonville’s Don Carey on Dallas’s Jason Witten (Carey was injured on the play, but Witten was not) and by New England’s Gary Guyton on Favre. One of the most critical hits of the weekend — the hit to Favre’s shoulder and chin by Patriots defensive tackle Myron Pryor that sent Favre to the locker room early — was clean. Did that hit affect scoring? Maybe, but not in the expected way. With Favre woozy on the sideline, the backup Tarvaris Jackson threw a touchdown pass.  Last week, when no hits to the head were flagged, games produced an average of 52.6 points, which was the highest average in 27 years, and the second-highest scoring weekend since the 1970 merger. (In Week 7 of 1983, games averaged 54.4 points.)  With video evidence confirming the confessions of a few players that they had pulled up on hits rather than risk a fine or suspension, the instant analysis determined the change in tackling had led to bigger plays and bigger scores.  Steelers linebacker James Farrior was skeptical of the link from the start. He had a simpler explanation: “Defenses might just be doing bad last week.”  A version of this article appears in print on November 2, 2010, on Page B13 of the New York edition with the headline: Week 8 and Other Mysteries of the Unexplained. Order Reprints| Today's Paper|Subscribe
Donovan McNabb is benched, Brett Favre praises himself, but the Cowboys’ collapse might provide drama for the whole season.