Iirc, playing at home is a bigger advantage in football than it is in baseball or hockey, but not as big as in basketball (in each case, at the sport's highest levels). The reasons why home court is big in basketball are self-evident to anyone who played the sport. I figured the gap in HFA between football, and baseball and hockey, was largely due to the impact of crowd noise. I didn't play any of those sports at a high level, however, so I could be all wet.I think the Gilette crowd always has been kind of blah -- mostly because of the shape of the stadium. However, I'm not sure it matters. Do people here think it matters -- like tangibly -- would the Patriots have won more home games the last 15 years if the crowd was better? Or are we purely talking about the fan experience? By my count on Football reference, the Patriots are 108-21 at home during the Billenium. I'm fine with saying our crowd kinda sucks, I just don't think it really matters outside of people that want to wear "12" shirts or whatever.
In any event, I don't know if the difference between a raucous crowd and a relatively tame one is big enough that we could say with any confidence that one (or more) of those 21 home losses in the past 17 years would've been changed into wins if the crowd in Foxboro was as noisy as, say, a typical crowd in Seattle or Kansas City.