SANTA CLARA -- The 49ers play the Denver Broncos on Sunday, which means San Francisco's offseason interest in Peyton Manning is sure to be dissected yet again.Whatever anyone believes regarding Jim Harbaugh's intentions with Manning, Smith says his relationship with his head coach is just fine."No awkwardness. I think anyone who's been around Coach Harbaugh for a while realizes, I think it's a great thing about him, he's going to tell you what he thinks. Good or bad," Smith said."He's going to give you his honest opinion and you appreciate that as someone who's been around a long time and been around coaches. You appreciate a guy telling you the truth and being honest with you even if it's not what you want to hear."Smith also appreciates Harbaugh's detailed coaching style and feels he is improved fundamentally because of it. As Smith enters his second year in the same system, the praise by his coaches and teammates this preseason is not over better footwork, but his mastery of the offense."(He) totally understands the offense now," said offensive coordinator Greg Roman emphatically. "He can recite things. He can fix things. Understands where people are. When you go back and look at our first early games last season, just getting through a straight progression was a work in progress relative to where it was late in the season relative to what it is now."He's getting through his reads quicker. He's eliminating reads earlier. Really just taking ownership of our offense. He understands all the different things that we do. He's really, really, really intelligent, bright football player. Really intelligent. He is super smart. Savant like at times."Dropping "really" four times to describe Smith's mental acumen may seem a bit much, but his teammates believe it's accurate."He's always learning. Always does a good job of just knowing completely everything," left tackle Joe Staley said. "He sits in our meeting sometimes and when we're going over our calls and stuff, just to get a better idea of what we're trying to do so he can be on the same page as us. His recall and his overall knowledge of the offense and what everyone is doing on every single play is amazing."Smith remains low key on his progress. His says his comfort level has allowed him to work at a quicker pace in training camp, and he has seen the benefits in the first two exhibition games. "We've ran the ball really well this preseason," Smith said. "Kept ourselves in better situations. We've been ahead of the chains. A lot of positive plays."The one area Roman would like to see Smith improve is his sack numbers. Opponents sacked Smith a league leading 44 times last season. Part of that was Smith taking what Roman called the "smart sack." In doing so, Smith threw a league-low five interceptions."The one thing that Alex did through all that, a historically great job of protecting the football," Roman said. Smith has yet to throw an interception this preseason though he was sacked twice in the two drives he led in the loss to the Houston Texans on Saturday.A point of emphasis is for the entire offense, from improved blocking to the receiver's gaining better separation, to reduce that sack number.Really, really, really, really reduce it.