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Bradley Roby has been playing outstanding, but he can get a little shaky in coverage every once in a while (to be expected as a rookie). That being said, I was surprised to see him matched up with Sammy Watkins so many times in the 4th quarter, especially on the 4th-and-16 conversion. Why not just have Chris Harris, Jr. follow him to close out the game?
-- Chris York

There's a couple of reasons.

Let's start with skill sets. When the Broncos go into their nickel alignment and use Harris as the slot cornerback, that maximizes their flexibility with Harris. He can follow a receiver in motion; he can provide run support; he can blitz, at which he is effective and notched a sack Sunday.

The slot man also has more responsibilities; he's watching routes in the flat, in addition to his own man. When Harris works outside, teams can simply avoid that side if they don't want to risk throwing into the "No Fly Zone" manned by one of the best technical cornerbacks in the game; that's not the case when he's on the inside.

Roby has the skill set in terms of size, speed and athleticism to take on receivers like Watkins. But there will be ups and downs.

"I don't know that anybody could have predicted that he could have played the role that he's played and played as well as he's played for us," said Defensive Coordinator Jack Del Rio. "It hasn't been perfect, but it never is. And that's what I've explained to him: as long as you're competing, playing with great technique and going after it every week, you'll get better, you'll learn from the experiences you have. And I think that's what he's doing right now, and I'm sure glad we have him."

And those experiences are universal to NFL cornerbacks. Roby can ask Harris about those -- just look back at Harris' first start, against Detroit in 2011, when the Lions re-aligned before the snap to set up duels between Harris and Calvin Johnson. Harris grew from that day into the player he is now.

And that sets up the other reason: if you want Roby to become all he can, he needs to work on the outside, against uber-athletic receivers like Watkins. He needs to be tested. And there remains plenty to like about Roby: he limits yardage after the catch (an average of 3.4 yards according to ProFootballFocus.com), and has shown some spark when he plays with aggression. A key step will be reducing his missed tackles, but he's become steadier in coverage since November began.

As you noted, some shakiness is expected. But this is how he learns. With a 14-point lead, the dink-and-dunk heavy Bills out of timeouts and just 3:33 remaining, that's a good opportunity for Roby to be in such a matchup. And it was a learning experience.

"Really some sloppiness with technique, but, no, he's had a good year," Del Rio said. "A little bit like Kayvon (Webster) last year -- he had a much better year than people (thought). People remember one game against San Diego here where they went after him a bit, but if you look at the body of work, he played very well last year and that's what Bradley's doing for us right now."

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My question is about the fourth quarter last Sunday The Broncos defense and offense seemed to play very conservative. Any thoughts on why this play-calling was used with so much time left in the game?**
-- Shawn Over

Yes, and my thoughts start with the game situation. The Broncos led by three scores in the fourth quarter against a team whose quarterback was willing to take checkdowns. As I noted last week, where the Bills can beat you is with explosive plays of 25 or more yards; when those are limited or eliminated, Buffalo loses.

When you're working with a two- or three-score lead in the fourth quarter, let's face it, you're trying to get to the end with the best result. Everything must be evaluated on a risk-reward basis. And remember, the Broncos were without Julius Thomas, had a hurting Jacob Tamme (rib injury the last two weeks) and a hindered Demaryius Thomas (ankle bruise).

With those considerations, the chances of a clock-stopping negative play in the passing game increased. Obviously, such a play does not exist on the ground unless a ballcarrier channels his inner Marion Barber III. Therefore, on the Broncos' three-and-out with 5:25 remaining, they ran three times -- and forced the Bills to use all three timeouts. (In a vacuum where the injury situation is not considered, the Broncos' win probability per AdvancedNFLStats.com dropped from 99.8 percent to 99.7 percent after the three-and-out, for what it's worth.)

And the defense wasn't happy with its fourth-quarter play late in the game. Harris and Terrance Knighton both expressed frustration, understanding that the defense needed to finish better. And if the defense had gotten off the field on a fourth-and-16, I don't think I'm writing about this.

I would love to see them target Virgil Green 5-6 times a game and see how he does. Your thoughts?
-- Jim Berve

Any offense wants to diversify its options, and we know that Peyton Manning would like to get Virgil Green his opportunity to score a touchdown; he's mentioned that in recent weeks.

But at the same time, the Broncos have had four years to assess Green's strengths and weaknesses, and to adapt accordingly. And with Julius Thomas a good bet to be back in uniform this weekend, it would appear that Green's opportunity to become a more prominent target has passed -- at least, for the moment. It could come again if Thomas' ankle injury causes further problems.

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Hey Mase, do you think that this late-season run game is designed to give the passing game time to heal before the post season? Side question, do you think that Peyton didn't break Drew Brees' record on purpose? ** -- Michael Pack

In the short run, it's designed to take advantage of personnel and matchups that are in front of the Broncos. With Julius Thomas out and replaced by Green, the personnel is tilted more toward the run game, so that's the short-term benefit. In the long run, it forces a greater burden on the safeties, which at some point will have to account for the run, and bring an extra man into the box, which in turn opens up the passing game.

"We're hoping that one day, where (the defense) decides to bring that eighth guy down into the box, we let 18 (Manning) do what 18 does best, so it kind of [becomes] pick your poison," said running back C.J. Anderson.

And as for your side question, no, I don't think there was any intent. These things happen in the course of a game. Manning's only concerned about getting the football across the goal line; it doesn't matter how. And there's not a quarterback in the sport who would avoid breaking a record "on purpose."

The Seth Lobato tryout at QB has risen the level of fans; concern for the future of Dever QBs. Our recently playing against Kyle Orton and his being booed by 'fans' calling for Tim Tebow, amidst our new effective emphasis on the run game, has all four QB's in high relief, six if you count Osweiler and Dysert. What is your inside take? My expectation is status quo.
-- Donald Rogers

First of all, don't read anything into the tryouts for this year, unless injuries strike a specific position. It's common for teams to have several to over a dozen players in for Tuesday tryouts -- especially at this time of year, now that the Canadian Football League season is done and its league's players can pursue opportunities south of the 49th parallel. You're focused on finding players to sign to reserve-future contracts next month so you can get a look at them throughout the offseason.

If you add a quarterback in the reserve-future window next month, it's just for competition on the back end of the roster and to get a longer look at someone that you might have liked when he was draft-eligible, and nothing more than that. The Broncos carried four quarterbacks last offseason after signing undrafted rookie Bryn Renner; it would be no surprise if they had four quarterbacks again throughout the offseason.

Second, in the point of the chants for "Tebow" -- the fans weren't calling for him. The fans were trying to taunt Orton, since Tebow took his starting job four and a half games into the 2011 season.

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