I agree with John Clayton of ESPN:
What the NFL is seeing is history in the making. Brady has 21 touchdown passes in six games, putting him on pace to throw 56 TD passes, seven more than Manning's record of 49. Brady is completing 72.5 percent of his passes, which could shatter Ken Anderson's completion record of 70.55 set in 1982. Brady's current quarterback rating of 128.9 tops Manning's 121.1 season record set in 2004.
ugly tuna