The difference is like that between a Ford and a Ferrari.
Let me explain.
During Carolina's preseason game against Chip Kelly's up-tempo offense at Philadelphia, the only thing that stopped the Eagles was turnovers; they led in yardage (257 to 162) and first downs (17 to 9). Quarterbacks Michael Vick and Nick Foles were 15-for-18 passing for 158 yards and two touchdowns.
All this in the first half.
Granted, it was a meaningless game and the Panthers were vanilla on defense. But Philadelphia proved in Sunday's opener that it works, torching Washington for 33 points and 443 yards.
Coach Doug Marrone's offense at Buffalo has a ways to go to reach that level of efficiency with rookie quarterback EJ Manuel. They managed only 15 first downs and 286 yards in a 23-21 loss to New England.
"They get plays off fast,'' Carolina defensive end Greg Hardy said. "You can't get plays off that fast if you get hit in the mouth by Kraken [Hardy's nickname for himself] all day.''
There is that.
New England actually ran 28 more plays than Buffalo -- 89 to 61-- and had 11 more first downs. The Bills in particular couldn't move the chains in the fourth quarter when it needed to protect a lead.
This isn't the "K-Gun'' no-huddle offense the Bills ran in the 1990s with quarterback Jim Kelly.
Still, it helps the Panthers to have faced the Eagles.
"You have an understanding as to what it's like, what it's going to be,'' coach Ron Rivera said. "The most important thing is when you play these up-tempo teams is if you can control the chains. Three-and-out, it doesn't matter. Now your offense is back on the field.
"You want to slow them down and get them off the field.''
Carolina has the defense to do that, particularly against the Buffalo running game of C.J. Spiller and Fred Jackson. Spiller, supposedly the centerpiece of the Bills' offense, was limited by New England to 41 yards rushing on 17 carries and five catches for 14 yards.
The Panthers are coming off an impressive performance in which they held the Seattle Seahawks to 12 points and 70 yards rushing.
Where Carolina struggled was allowing quarterback Russell Wilson to get out of the pocket and complete passes. Manuel, who had preseason knee surgery, may be more easily rattled with only one game's experience.
"I'm glad we faced Philly in the preseason,'' Carolina strong safety Charles Godfrey said. "We started off real slow. We had to get into a groove. Now going into this game we know what to expect.''
And the good news, it's Buffalo and not Philadelphia.