ENGLEWOOD, Colo. -- Here's a look at the first half of the season for the Denver Broncos (6-3) and a preview of what to expect in the second half:

Grade: B Blame the Broncos for raising the bar after five consecutive division titles to go with two Super Bowl trips in the past three seasons. They’ve been good -- at times very good -- but even they have said it isn’t good enough. The defense has been top shelf for the most part, but a propensity for allowing big plays on the ground -- highlighted by the 218 rushing yards the Raiders piled up Sunday -- when games are in the balance is troubling. But the biggest issue is the offense has been choppy with running back C.J. Anderson on injured reserve. The Broncos' running game hasn't been strong enough for defenses to respect the play-action pass. And until the ground game improves, this team will not not reach its potential.

Midseason MVP: Virtually all of the candidates are on the defensive side of the ball. Safety T.J. Ward is certainly more than deserving as he has been asked to move all over the formation and played at an All-Pro level. But stopping linebacker Von Miller has been the focal point of every offense the Broncos have faced. He has consistently faced waves of blockers trying to slow him down, and he leads the league 9.5 sacks. DeMarcus Ware missed five games with a fractured forearm, but has returned to the lineup so Miller’s impact should only increase.

Best moment: The Broncos hope there are better moments ahead, but the one that encapsulated how they do their business came in the closing minutes of the Week 2 win over the Indianapolis Colts. The Broncos were protecting a six-point lead with less than two minutes to go in the fourth quarter and Colts quarterback Andrew Luck was set to wing it around. But on the first play of the drive, Miller sacked Luck, knocking the ball free. Shane Ray scooped up the fumble and returned it 15 yards for a touchdown. Miller later sacked Luck again on the last play of the game.

Worst moment: There are actually three since the Broncos have had three members of the team leave a stadium in an ambulance this season. Coach Gary Kubiak was taken to a Denver hospital following the team’s loss to Atlanta because of what was later diagnosed as migraine condition. Kubiak was then advised by doctors to stay home for a week so he was not on the sideline for the loss in San Diego. Tackle Russell Okung was taken to the hospital after that loss in San Diego with concussion-like symptoms. And defensive coordinator Wade Phillips was taken to the hospital before halftime of the team’s win over San Diego after a sideline collision with Chargers running back Melvin Gordon.

Player to watch: In the youth-is-served backfield with a 24-year-old first-year starter at quarterback in Trevor Siemian and a rookie fullback in Andy Janovich, it is rookie running back Devontae Booker who has more on his plate than expected. With Anderson on injured reserve, Booker must power the running game, which needs to improve if the play-action game is going to open up. Booker has lost two fumbles in limited touches in eight games. That is something he has to avoid as the Broncos maintain playoff momentum.

Second-half outlook: If the Broncos want their Dec. 18 game against the New England Patriots in Denver to mean something, they’ll have to do some heavy lifting on the road especially with that third loss they're now carrying around after the trip to Oakland. In the second half of the season, they have five road games overall. Their Super Bowl chances will rest on how much improvement they can make on offense, and there's plenty of room for it, and how well they maintain their edge on defense -- or roughly the same formula they used last season on the way to the team’s third Super Bowl win.