The long-running title of this in-game NFL reaction piece is Booms and Busts.

For the early window of Sunday's Week 1, we could have easily changed it to Busts and Busts.

It's generally a question of rest versus rust when the NFL hits the opening weekend, as modern strategy slants toward resting primary players through most (perhaps all) of the preseason schedule. With that in mind, often it takes time for offenses to find their rhythm, for skill players to spread their wings.

Rust was the winner in Sunday's first eight games. Several signature players and offenses underperformed, and seven of the games fell under their posted total.

49ers put on a show in opener

We'll meander through the wreckage shortly. But let's lead with a positive story. The 49ers entered the season as one of the primary Super Bowl favorites, and they smashed in their first assignment, a 30-7 domination of the Steelers.

If anything, the final score feels misleading — the game was never competitive. San Francisco mixed efficiency with splash plays, and totaled 391 yards of offense against a strong Steelers defense. Maybe there are several right answers on this Niners offense.

Brock Purdy wasn't an early fantasy pick, but the quality of his play connects the entire offense. And Sunday at Pittsburgh, he looked like a seasoned veteran. Purdy completed 19 of 29 passes for 220 yards, tossed a couple of touchdowns and wasn't intercepted. The Niners converted 6 of 13 third downs and also picked up a fourth-down conversion. Purdy could have posted a big fantasy day, but the Steelers didn't fight back and the Niners took the air out of the ball in the second half.

Purdy wasn't perfect, of course. He took three sacks and fumbled twice, losing one. But after last season's UCL injury and a summer of uncertainty, it was encouraging to see him start so crisply.

Two San Francisco skill players percolated to the top of the Week 1 fantasy leaderboard — Christian McCaffrey racked up 169 total yards and a touchdown, and Brandon Aiyuk sprung for eight catches for 129 yards and two scores. Aiyuk also had a killer downfield block on McCaffrey's 65-yard scoring jaunt.

McCaffrey's play is no surprise — he was a Top-5 pick everywhere, and generally the top running back pick in all pools. Some had mild concern that he might cede a chunk of work to Eli Mitchell, but that wasn't the case Sunday — McCaffrey collected 25 touches, Mitchell just five (all carries, netting a mere 10 yards).

You don't want to overreact to small samples, but it's fair to wonder if Aiyuk (Yahoo ADP 64) was a shrewder pick than running mate Deebo Samuel (Yahoo ADP 40). It's not that Samuel coated himself in shame after a 63-yard day (five catches, two runs). But given the narrow gap in their respective projections, the two-round discount on Aiyuk might have been a gift.

George Kittle also had a quiet game, catching 3 of 6 targets for a piddly 19 yards. Hey, at least he was able to play. Tight end attrition was one of the frustrating themes of the day, league-wide.

The good times should keep rolling for the Niners' offense. The next three weeks, San Francisco draws the Rams, Giants and Cardinals.

Steelers lay an egg

The Steelers, of course, can't blame their play on rust. Pittsburgh used its first-string offense for five summer possessions, all touchdowns. Kenny Pickett was one of several breakout candidates featured on this offense. The Steelers weren't rusty Sunday, they were just badly outplayed.

Pickett managed only 5.0 YPA and threw a couple of picks over 46 attempts. His short touchdown to Pat Freiermuth was a nifty throw, but too many of his other tosses were late or off target. No one in the Pittsburgh receiving game did much; only forgotten Allen Robinson II topped 50 yards, and Diontae Johnson left in the third quarter with a hamstring injury. George Pickens had a quiet 5-36-0 on seven looks.

The Pittsburgh running game was also stuck in the mud. Najee Harris had one 24-yard run but his other seven touches went nowhere (9 total yards). Jaylen Warren had eight touches for 18 yards.

The one silver lining for Pittsburgh — it's an out-of-conference loss and it's to a loaded opponent. It's to some degree an excused absence. But the work won't get much easier next week, hosting a Cleveland defense that dominated the Bengals for three hours Sunday.

Several teams come out of the gate slow

The Steelers had plenty of company in the disappointing file. Have a look at some of the other frustrating performances in Sunday's early window.

• Is Arthur Smith crazy like a fox or just a little crazy? The Falcons disposed of Carolina, but Atlanta's collection of first-round draft talent was underwhelming. Bijan Robinson was fine (10-56 rushing, 6-27 receiving, one brilliant score), even as his managers didn't want to see Tyler Allgeier run for 75 yards and two scores. But the Falcons attempted only 18 passes and most of them went away from Kyle Pitts (2-44-0, 3 targets) and Drake London (no catches, 1 target). Again, the Falcons won the game, so there's no urgency to change anything.

• Cincinnati's no-show at Cleveland wasn't that big a surprise, given that Joe Burrow missed most of the summer work and the Browns traditionally defend the Bengals well. A steady rain didn't help, either. Burrow had a nightmare day (82 passing yards, only six first downs), but better days will come soon. Ja'Marr Chase managed just 5-39-0 on 9 targets and Tee Higgins was catchless on 8 targets, a fairly rare occurrence. I'd trade for any of these guys tomorrow.

• Cleveland's winning script was familiar: a staunch defense and lots of Nick Chubb (127 total yards). The Deshaun Watson redemption will have to wait; he struggled to 5.3 YPA and misfired on several attempts. Watson at least salvaged his fantasy day through 45 rushing yards and a touchdown; he also threw a touchdown pass to backup tight end Harrison Bryant. Elijah Moore and Amari Cooper both saw 7 targets but didn't do much with them (43 and 37 yards, respectfully).

• Your heart feels for J.K. Dobbins, who tore his Achilles and is done for the year. It will be interesting to see if the Ravens kick the tires on a free-agent back because Gus Edwards and Justice Hill don't sound like enough for a playoff-contending backfield. Rookie Zay Flowers was the target hog in the passing game (10 targets, 9-78-0), while morning penny stock Isaiah Likely did almost nothing (a single grab for 4 yards). Odell Beckham Jr. made one highlight catch, but 2-37-0 on 3 targets doesn't move the needle.

• I was relieved when Washington finished off Arizona, saving my survivor sheets for another week. But the Commanders' offense didn't meet my lofty expectations; Brian Robinson averaged just 3.1 yards per carry (though he had a short touchdown catch), and Jahan Dotson (5-40-0) and Terry McLaurin (2-31-0) finished under their projections. Sam Howell was skittish in the pocket at times, taking six sacks, fumbling once and throwing a pick (at least one other pick was dropped).

The Commanders seemed to pull back from Howell in the second half, draining the clock and winning the game through defense. It's not that Howell can't be a breakout player — or Dotson, for that matter — but we need to see a lot more. The schedule gets nasty, with Denver, Buffalo and Philadelphia lying in wait.

Speed Round

• The Patriots had a significant yardage edge on Philadelphia, and defended Jalen Hurts very well. And having Bill O'Brien run the offense is a breath of fresh air. New England still might be the worst team in the AFC East, but they have the look of competitive. Perhaps Mac Jones can support Hunter Henry as a Top 12 tight end.

• You needed the right draft slot to land Tyreek Hill, but if you targeted Tua Tagovailoa, you might roster him everywhere. If Miami can keep its triplets healthy, this offense could go to the moon. Mike McDaniel knows how to scheme his elite talents open, and no one can run with Hill anyway.

• Sean McVay pantsed the Seahawks for three hours, a lovely game plan. And Puka Nacua feels obvious now, hiding in plain sight. As my colleague Matt Harmon pointed out, there's a fair amount of overlap in Nacua's preferred routes and things that the Rams like to do with Cooper Kupp. It doesn't make Nacua a full replication of Kupp, no one would say that, but it makes Nacua worth some aggressive FAB chase during the week.

• My college buddy Mike had a choice last month in a hybrid-scoring league; keep George Pickens or the Dallas defense. It's a league with very unusual (and ambitious) defensive scoring. I hope you kept the Cowboys, Duke.