I've posted this before, but I think the light air @Den really affects his deep ball more than the cold. TB consistently overthrows receivers on deep balls (where the altitude would have the most pronounced effect), and maybe the ultra low humidity hurts his grip/accuracy other times. But even on short throws the low pressure will have an impact on speed and carry.
For a QB as precise as TB it probably worse than most. If your normally precise ball travels an extra 3% out of the blue on game day, it might start messing with your head. I think NE should show up @Den a day earlier and let TB get used to the altitude effect on his throws; it might make a difference.
He's had this happen (overthrows) pretty much every game @Den despite whatever the temp that day. And it seems the only stadium I've seen it happen more than once to make me think it might be something other than just bad luck. And the phenomenon I mention is real enough for studies and have a name (ref: Coors Field Effect) and shouldn't readily be discounted at least as a partial explanation for TB's accuracy woes at Mile High.
edit: The effect in Denver's altitude is a ball travels +7.5% further than sea level. Not 3%. A 50 yd pass by TB in Den will carry nearly 4.0 yards further than he expects. A decision honed by years of practice and thousands of throws, hard wired into his muscle memory and triggered in a split second to determine how to apply just the right throwing force. I'd imagine it would be tough to convince yourself and execute in the split second that you need to throw it a bit softer when all your instincts and years of training are screaming at you to grip it and rip it like you've trained to do. Hence, the only advice that I think would work, is to get up a day early (or even two days or more - but that's obviously not practical) and acclimate oneself to the effect. I guess they could stay closer, maybe take a field trip to Mt Washington, hike the mile above sea level, and have a quick practice there
I wonder if I can find opponent comp% for long passes in Den over the years to see if this effect is real across other teams and players. Edit: I cant find this data, if anyone finds it plz post...