[fortheDeclaration]

This goes beyond one game.

An underinflated ball in cold weather gives that team a big advantage.

[Colofornian]

This goes beyond one game. An underinflated ball in cold weather gives that team a big advantage.

Well, and it's both cold weather -- and especially wet weather...at least as it applies to receivers hanging on to the ball.

This goes beyond one game

Yes, and the preliminary review of the stats seems to bear this out:

1: Fumbles Before & After League Allows Teams to Supply Own Footballs

2006: Brady & Peyton Manning lobby NFL to use their own footballs -- instead of NFL supplying them.

2007 NFL allows it.

2000-2006 Pats are around even with rest of the league, averaging a fumble every 42 touches.
2007-2014 when rule is changed: Pats suddenly set fumble-free records, averaging a fumble every 74 touches.

2. Brady's Completion % Before & After League Allows Patriots to Use Own Footballs

2000-2006: 60.9% -- including 61.8% in 2006
2007-2014: 64.7% -- including 68.9% in 2007...

Brady's completion skyrocketed 11.5% (career-high 68.9%) in a single season! The main difference, it seems, 'tween '06 and '07 was that Brady got to use his own footballs!
See Tom Brady: Career Stats

In fact thru 2006, Brady was consistently at 60%...61%..62%...63%

Then he gets his own footballs...
07: 68.9%
08: Injured
09: 65.7% (even coming off of injury season was better than he ever was in using NFL-supplied footballs)
10: 65.9%
11: 65.6%
(he was back down in 12 & 13...But in '14 was higher than any single season 2001-2006

I maintain, actually, that just as a slightly deflated football results in less fumbles, that the same can be said for receivers pulling in passes...less dropped passes.

So actually -- deflated footballs helped the Pat receivers more than it did Brady himself...but still...if done game after game...result?...a much higher completion %

More statistical research needed:

Like:
Did Patriot dropped passes suddenly decline 2007-2014 to complement sudden fumble-free football?
Secondly, did Patriots' fumble-free football ONLY apply to RB & WR since 2007 (using possible deflated footballs?) Or, if it was better quality ball-handlers, did the fumble-free football carry over to the special teams since 2007?