There's a rule in August: Never overreact to the preseason.
Having said that, you can learn things by watching closely. Preconceived notions can be proven right or wrong. You can identify harbingers of things to come.
And yes, we occasionally break the rule by overreacting. (Nobody's perfect.)
Here are my biggest observations from Week 1 of the NFL's preseason, Schein Nine style:
1) Philly left searching for Big Foot
As regular readers of this column know, I call Sam Bradford "Big Foot" because I've heard rumors about the oft-injured former No. 1 overall pick being a franchise quarterback, but -- like the mythical beast -- I never actually see it. Chip Kelly did the smart thing, keeping Bradford in bubble wrap for the Philadelphia Eagles' preseason opener. While Bradford has looked good and healthy in recent weeks, you just can't subject him to too many live hits before the regular season.
Having said that ... Eagles fans got a glimpse of how things will go if Bradford gets hurt, and it wasn't pretty.
Mark Sanchez had a big-play opportunity on Philadelphia's first offensive snap, but he underthrew tight end Trey Burton, who was 5 yards clear of the nearest defender. In drive No. 2, Sanchez overthrew Jordan Matthews on a would-be touchdown strike. All in all, Sanchez finished an erratic 2-for-7 with 52 yards passing and a touchdown. And honestly, that stat line, though underwhelming, actually looks much better than it should. Sanchez's 34-yard touchdown pass to Nelson Agholor was actually such a wretched throw that it lured the pick-hungry cornerback out of position; Agholor made a fantastic play on the ball and scampered all the way to the end zone.
Look, I've seen the Mark Sanchez movie many times. I know how it ends. So do Eagles fans, who saw the signal caller come up short in a season-crushing, three-game losing streak to Seattle, Dallas and (gasp) Washington last December. Meanwhile, Matt Barkley is Matt Barkley, Tim Tebow is Tim Tebow. (See: non-answers at the position.) Thus, Kelly desperately needs Bradford's best ability to be his availability in 2015.
Overall, I really like what Kelly did this offseason, revamping the roster in an aggressive -- but largely wise -- manner. If Bradford is healthy, I like the Eagles to win the NFC East. But I acknowledge that's a major roll of the dice. And if Bradford isn't healthy -- if Philly doesn't get solid play at the game's most important position -- the extreme makeover falls flat.
2) White makes Bears blue
The one thing every single NFL coach desires most in the preseason when it comes to his players: good health. With that as a backdrop, the Chicago Bears suffered a crushing blow to their already-slim chances for rebirth under new boss John Fox in 2015. The Bears announced Saturday that first-round pick Kevin White needs surgery after developing a stress fracture in his shin. The dynamic wideout first felt the pain in June OTAs. Rest and therapy didn't cure it. The No. 7 overall pick will begin the season on the physically unable to perform list and could miss his entire rookie campaign.
Oof. This development solidifies Chicago's role as the bottom feeder in an otherwise-competitive NFC North.
As stated before, I can't see how Jay Cutler's dispirited demeanor will jibe with Fox's infectious energy. And White being sidelined for the foreseeable future certainly isn't going to help No. 6's morale. Looking at the other side of the ball, Fox and defensive coordinator Vic Fangio have plenty of work to do. The first-team defense was surgically dismantled in the opening drive of the preseason by Ryan Tannehill and the Dolphins. Jared Allen was left seeking a silver lining of sorts: "It's a good little slice of humility and it lets you know where you are at and things you can work on."
3) Teddy Time is nigh!
Speaking of the otherwise-competitive NFC North ...
The Vikings' preseason date with the Buccaneers was hyped because it was the "debut" of Jameis Winston. And if you did indeed tune in to see impressive play by a promising young passer, you weren't disappointed: Teddy Bridgewater stole the show.
The Vikings signal caller came out in midseason form, completing seven of his eight passes for 86 yards. And for those who paid attention to the second-year pro's debut season, this can't count as a surprise. Teddy rocked steady in his rookie campaign -- sans Adrian Peterson after Week 1 -- improving as the season went along. Over the final five weeks of 2014, Bridgewater completed 72.1 percent of his passes and posted a 103.0 passer rating.
I think Bridgewater gets even more comfortable in Year 2 with fine offensive coordinator Norv Turner and enjoys a big season. As I wrote back in June, I think Mike Zimmer's Vikings can be akin to the Golden State Warriors. No, they're not going to win the Super Bowl, but these Vikes are young and exhilarating. I believe Minnesota, with Peterson back in the fold, is a playoff team.
4) Fear Ameer
On Thursday morning, I wrote that Ameer Abdullah was one of the true risers in NFL training camps. On Thursday evening, Abdullah made me look wise. Showing off speed, power, vision and awe-inspiring lateral quickness, the Lions' second-round pick shredded the Jets for 67 yards on just seven carries -- including a jaw-dropping 45-yard scamper. After the game, New York coach Todd Bowles brought up Motor City royalty: "He's quick as a cat. He's about as quick as Barry Sanders. I'm not saying he is Barry, but he's a good running back."
As I've said many times on SiriusXM this offseason, I think Agholor, Abdullah and Amari Cooper are the top three candidates for Offensive Rookie of the Year. Abdullah should get 20 to 25 touches a game for Detroit. Joique Bell should not be an option to start.
5) Full deck of Cards
Don't sleep on Arizona. Bruce Arians' team won 11 games last season and made the playoffs despite a wave of injuries that would've buried most teams. So what happens if this squad can stay relatively healthy in 2015? It's an enticing question.
Carson Palmer looked splendid in a brief appearance against Kansas City on Saturday night, completing all four of his passes for 77 yards. Andre Ellington looked healthy and showed sizzle -- particularly on a 57-yard catch-and-run out of the backfield. Tyrann Mathieu also appeared to have a clean bill of health, picking off an Alex Smith pass on the Chiefs' opening drive.
The Cardinals have the top head coach-general manager combo in the NFL today. And I think Arizona is the third-best team in the NFC, behind Green Bay and Seattle.
6) Garoppolo ... Yikes!
I like Jimmy Garoppolo. I blasted teams like St. Louis for bypassing him in the 2014 NFL Draft. I think he has a future in this league. But man, Jimmy G was brutal against Green Bay on Thursday night. Garoppolo completed 20 of his 30 passes for just 159 yards, with zero touchdowns and one interception. Oh, and he took seven sacks, for good measure. The second-year signal caller didn't display much awareness; consequently, the Pats fielded a pop-gun offense.
With Tom Brady's status still up in the air for the season's first quarter, Pats fans have to be champing at the bit for an appeal decision from Judge Richard Berman. If Garoppolo is under center in Week 1, will the Patriots beat the Steelers? I originally thought they would. Now? I need to see more ...
7) No ordinary Joe in Baltimore
I like the Ravens to win the AFC North in 2015. And while I acknowledge the superb job Gary Kubiak did as the offensive coordinator last year, the club shouldn't miss a beat with Marc Trestman taking over the reins.
Joe Flacco and the Ravens' first-team offense looked like a well-oiled machine against New Orleans, opening up the preseason with a 16-play, 80-yard touchdown drive. Flacco even busted out a 17-yard run!
The Ravens quarterback quietly posted a career-high 27 touchdown passes last season. In the postseason, he beat the Steelers on the road and then had the eventual Super Bowl champion Patriots on the ropes in New England. Flacco's name never comes up in the elite QB conversation, but do not overlook this cat in 2015.
8) Mariota and Winston look like ...
For both young quarterbacks, there were moments of futility and moments of promise.
I did like Marcus Mariota bouncing back after an early interception (which was somewhat shocking, considering his pick-free training camp). Meanwhile, I was alarmed by Bucs coach Lovie Smith calling his new QB's debut a "typical Jameis Winston day." If that's true, that's a huge problem.
9) Rams running amok
The Rams have talent -- especially along the defensive line -- spawning playoff chatter around St. Louis. But in the preseason opener at Oakland, Jeff Fisher's team committed 10 penalties and put three points on the board. The Rams' starters looked a bit lost and punchless.