DENVER --If you judge a preseason game solely by how it starts, the Broncos did just fine.
They ended the first quarter with a 7-0 lead and a 116-37 advantage in total yards. They averaged 6.1 yards per play, holding the 49ers to 3.7 yards a snap.
The 49ers did not do any damage until key starters like Chris Harris Jr., Von Miller, Brandon Marshall, Darian Stewart, T.J. Ward, Derek Wolfe and Sylvester Williams were done for the night.
But with a quarterback battle in play, a preseason game isn't just about the start.
It's four quarters -- and after a last-gasp Paxton Lynch pass was intercepted, it included four giveaways that doomed the Broncos to a 31-24 loss.
A quick postgame look at the three key areas to watch:
- THE ONGOING QUARTERBACK COMPETITION**
Lynch, Mark Sanchez and Trevor Siemian all had bright moments, but turnovers were their undoing.
"At the end of the day, it's your job to protect the ball," Head Coach Gary Kubiak said. "That's the most important thing. That's something that coming out of tonight wasn't good enough."
Siemian looked composed on his first drive, and relied on short passes during his one quarter-plus of work. Every one of his 14 passes was completed within 11 yards of the line of scrimmage.
But Siemian was also going heavily to his right -- and that cost him when Eric Reid jumped a route for Demaryius Thomas and returned it 42 yards for a touchdown eight seconds into the second quarter. His next pass was overthrown; the pass after that was dropped by Cody Latimer, and that ended his night.
"You just can't turn the ball over. I just made a bad decision," Siemian said.
Sanchez also started strongly. But he was undone by two fumbles on sacks late in the second quarter after the Broncos had advanced into the red zone.
After his first fumble, his play seemed to spiral. His final six pass plays included five incompletions and the second strip-sack fumble, dropping him from 10-of-12 to 10-of-17. "I just squandered a great opportunity to separate myself and put the team in a bad situation," a crestfallen Sanchez said after the game. "No excuse for that; poor, poor quarterbacking play."
As was the case for Sanchez, Lynch was also under duress from a heavy pass rush. But time and again, he showed his escapability, and his confidence appeared to mushroom every time he escaped the pocket, leading to two touchdown drives that nearly gave the Broncos a dramatic comeback.
But he also showed the kind of fortitude under pressure you want to see late in the fourth quarter, when he stood tall under a rush from Shayne Skov and fired a bullet for Durron Neal up the right sideline that hit the receiver in the hands before bouncing away.
Lynch delivered a perfect, 40-yard strike under a heavy rush. He was sacked on the next snap, but felt the rush from behind him enough to tuck the ball and prevent a fumble. Two plays after that, he rolled right, dodged two pass rushers, extended the play as he got to the sideline and then took the hit from Jason Faneca at the sideline that drew an unnecessary roughness penalty that kept the drive alive.
Lynch's ability to extend plays and his quick reads on slants allowed him to dice up the 49ers on two second-half touchdown drives.
"I thought he did great," Kubiak said.
- DEFENSIVE LINE**
Just three days after being helped back to the locker room after rolling his ankle, Derek Wolfe was dominant, blowing up two run plays and ensuring that Carlos Hyde finished the first quarter with just four yards on four carries.
But the Broncos' depth was tested and struggled. The line failed to generate the same kind of pressure it did in Chicago, and was often pushed back against the run, allowing the 49ers to rack up 177 yards on their next 28 carries -- a 6.3-yard average that allowed them to control the pace of the game.
The defensive line finished with no sacks and no hits on 49ers quarterbacks, after tallying one sack and three quarterback hits against the Bears.
3. SPECIAL-TEAMS COMPETITIONS
The challenge was different for Britton Colquitt than Riley Dixon. Two of Colquitt's punts saw the line of scrimmage in San Francisco territory, so the job was to drop it inside the 20. He did that, placing one punt at the San Francisco 9 and the other at the San Francisco 11.
Dixon's 51-yard punt midway through the fourth quarter was the longest of the night. But with a long field, his other two punts sailed just 34 and 36 yards. One resulted in a fair catch and the other in a muffed return, but he'll need to get more distance at that point on the field.
On returns, the results were mixed. Raymond had more chances, fielding four kickoffs and averaging 20.8 yard per return. Addison had a single kickoff return for 21 yards. Neither gained much traction on punt returns. Addison also had a costly drop on third-and-3 with 8:48 remaining in the fourth quarter, forcing the Broncos to punt with a 24-17 deficit.