Bill Belichick stated that the New England Patriots "followed every rule" in preparing their footballs for last Sunday's AFC Championship Game, offering several potential reasons behind the "Deflategate" controversy that has followed his team during the last week.
The Patriots coach addressed the issue during an unscheduled availability Saturday afternoon, one day after the NFL announced that it has not drawn any conclusions yet on how the team used underinflated footballs during the first half of its win against the Indianapolis Colts at rain-soaked Gillette Stadium.
"I believe now 100 percent that I have personally and we as an organization have absolutely followed every rule to the letter," Belichick said, while acknowledging that he felt compelled to speak up and address the questions raised by the controversy in the past week.
After detailing the organization's preparation process and suggesting that weather conditions may have affected the air pressure in the footballs, the longtime Patriots coach emotionally defended his team, saying, "We did everything as right as we can do it."
"At no time was there any intent whatsoever to try to compromise the integrity of the game or to gain an advantage," he said.
Belichick also said he has learned more about the science of air pressure in the past week than he had from a lifetime around the game. He could not provide specific answers as to why 11 of the Patriots' initial 12 game balls in the AFC title game were underinflated, but he explained how other things such as temperature could have an effect.
"So, I just want to share with you over the last week, I'm embarrassed to talk about the amount of time I've put into this relative to the other important challenge in front of us," Belichick said, referring to the team's Super Bowl matchup against the Seattle Seahawks next Sunday. "I'm not a scientist. I'm not an expert in footballs. I'm not an expert in football measurements. I'm just telling you what I know.
"I'm not going to say I'm Mona Lisa Vito of the football world as she was in the car expertise area, all right?" Belichick continued, referencing Marisa Tomei's character in "My Cousin Vinny."
While describing how the Patriots "simulated a game-day situation in terms of the preparation of the footballs," he remained adamant that the team had done everything correctly in the process of preparing its game balls.
"When the footballs are delivered to the officials' locker room, the officials were asked to inflate them to 12.5 PSI," he said. "What exactly they did, I don't know. But, for the purposes of our study, that's what we did. We set them at 12.5 [PSI]. That's at the discretion of the official regardless of what we ask for, it's the official's discretion to put them where he wants. Again, that's done in a controlled climate.
"The footballs are prepared in our locker room. They are delivered to the officials' locker room, which is a controlled environment. ... When the footballs go out onto the field into game conditions, whatever those conditions are, whether it's hot and humid, cold and damp, cold and dry, whatever it is, that's where the footballs are played with, and that's where the measurements would be different -- possibly different -- from what they are in a controlled environment, and that's what we found."
NFL rules state that footballs must have air pressure between 12.5 PSI and 13.5 PSI. Patriots quarterback Tom Brady said Thursday that his preference is for the balls to be at the minimum legal level, right at 12.5 PSI. Belichick explained Saturday that the Patriots' experiment revealed how a properly inflated ball could lose air pressure due to variables such as weather and temperature.
Heavy rain and strong wind were in Foxborough the night of the AFC Championship Game. Temperatures were in the low 50s and high 40s.
"We found that once the footballs were on the field over an extended period of time, in other words they were adjusted to the climatic conditions and also the fact that the footballs which an equilibrium without the rubbing process after that had run its course and the footballs reached an equilibrium, that they were down approximately 1.5 pounds per square inch," he said. "When we brought the footballs back in after that process and retested them in a controlled environment as we have here, then those measurements rose approximately 0.5 PSI. So the net of 1.5 [PSI] back down 0.5 [PSI] is approximately 1 PSI."
Belichick also noted that the feel of the ball -- not the air pressure -- is the top priority in terms of the Patriots' preparation.
"I think the most important part of the football for the quarterback is the feel of the football," Belichick said. "I don't think there is any question about that and the exterior feel of the ball is not only critical, but it's also very easily identifiable.
"When I feel a football, I can feel the difference between slippery and tacky. I can feel the difference in the texture of the football of what degree it's broken in."
Belichick went on to say that determining air pressure wasn't as readily apparent as texture.
"The pressure of the footballs is a whole different story," he said. "It's much more difficult to feel or identify. So the focus of our pregame preparation for the footballs is based on texture and feel. I think Tom went into that extensively on Thursday and he obviously could go through it a lot better than I can because he obviously is the one touching them, but that's the heart of the process."
Belichick said that Brady and backup QB Jimmy Garoppolo had trouble detecting small differences in air pressure.
"We had our quarterbacks look at a number of footballs, and they were unable to differentiate a 1-pound-per-square-inch difference in those footballs," Belichick said. "They were unable to do it. On a 2-pound differential, there was some degree of differentiation but certainly not a consistent one. Couple ones they could pick out, but they were also wrong on some of the other ones that they had. So you're welcome to do that [test] yourself. I can tell you from all the footballs that I've handled over the last week, you can't tell the difference if there is a 1 PSI difference or a 0.5 PSI difference in any of the footballs."
In terms of how the Patriots prepare their game balls, Belichick said that they discovered it typically adds about 1 PSI to the ball's air pressure.
"That process of creating a tackiness, a texture, the right feel whatever that feel is a sensation for the quarterback, that process elevates the PSI approximately 1 pound based on what our study showed, which was multiple footballs, multiple examples in the process as we would do for a game. It's not one football."
Belichick said that all of the various factors that can affect air pressure are the likeliest explanation of how the Patriots' game balls came to be underinflated. The Colts' game balls were found to be at proper weight.
"The process, the whole thing is much more complex and I mean, there are a lot of variables that I was unaware of," he said. "It sounds simple and I'm not trying to say that we are trying to land a guy on the moon, but there's a lot of things here that a little hard to get a handle on and there was a variance in so many of these things."
While Belichick was steadfast in defending the Patriots' integrity and honesty concerning "Deflategate," he did acknowledge wrongdoing in the "Spygate" controversy when questioned Saturday.
The Pats were docked a first-round draft pick and fined $250,000 and Belichick docked $500,000 for illegally taping the New York Jets' defensive signals during a September game in 2007.
"Look, that's a whole 'nother discussion," he said when asked by a reporter whether he stopped "pushing the envelope" on the rules after the incident. "The guy's giving signals in front of 80,000 people, OK? So we filmed him making signals out in front of 80,000 people like there were a lot of other teams doing at that time, too. Forget about that.
"If we were wrong, then we've been disciplined for that.
"The guy is in front of 80,000 people. 80,000 people saw it. Everybody on the sideline saw it. Everybody sees our guy in front of 80,000 people. There he is. So, it was wrong and we were disciplined for it. That's it.
"Again, we are never going to do it again and anything that's close, we aren't going to do it, either."
Belichick stressed Saturday that he errs on the side of caution with NFL rules.
"We always do, but I mean anything that's even remotely close, we are on the side of caution," Belichick said.
He also said "Deflategate" is something he will not discuss in the near future.
"This is the end of this subject for me for a long time, OK?" Belichick said. "We have a huge game, a huge challenge for our football team and that's where that focus is going to go."
ESPN.com's Lee Schechter and The Associated Press contributed to this report.