Greggo's defense is designed to bully weak offenses and rookie QBs. Against feeble opponents, they look amazing. Against anyone else, they are very vulnerable. My lasting memory of Greggo was him slamming his clipboard on the ground as the Patriots ran yet another successful misdirection screen pass for a huge gain against him, circa 2002. Pretty sure it was Kevin Faulk.
EDIT: yup here it is:
https://www.upi.com/New-England-38-Buffalo-7/61961036371084/
"Running back Kevin Faulk turned a screen pass into a 45-yard scoring play with 7:33 left in the third quarter to increase New England's lead to 24-7."