Yet, based on the 23-year-old's intangibles, testimonials from his teammates and coaches, his solid performance in a 15-10 loss to the undefeated Philadelphia Eagles on Sunday and the relative job security granted by the Ravens' investment of a five-year, $8 million contract, Boller still appears to have an upside somewhere on the horizon.
"The expectations are higher," Ravens coach Brian Billick said of Boller, the first quarterback to start consecutive season-openers since his tenure began in 1999. "The concept that he's had a full season behind him now, those lessons that you learn, we're counting on in the second half of the season to kick in and be a difference."
In games that Boller has started over the last two seasons, the Ravens are 9-7 overall. He has completed 212 of 390 passes for 54.4 percent accuracy for 2,219 yards, 10 touchdowns and 15 interceptions.
The former Cal-Berkeley star has a cumulative 63.6 passer rating.
Boller has passed for less than 100 yards six times. Thirteen times, the upbeat Southern California native has failed to surpass 160 yards passing. Meanwhile, Pittsburgh Steelers rookie quarterback Ben Roethlisberger has thrived, going 5-0 as a starter.
"I feel like this is the first game of my second season," Boller said. "I'm going to continue to work hard and try to do better."
Against the Eagles, Boller established career-high marks for completions and completion percentage.
Boller was a part of the solution for a change, not the major identifiable problem as the Ravens lost to Philadelphia without three Pro Bowl players: offensive tackle Jonathan Ogden, running back Jamal Lewis and tight end Todd Heap. Boller completed 24 of 32 passes for 63.2 percent accuracy and 223 yards with his first touchdown pass since Oct. 4 against the Kansas City Chiefs. He executed a conservative short passing game with efficiency. His lone interception came on a desperation heave at the close of the first half.
"I think it was a good game and we moved the ball efficiently," Boller said. "They were a great defense and I think we can build off of that performance. We were productive.
"It's tough because we got the loss. We have the chance to get that bad taste out of our mouths. I want to go out there and do what I've been doing."
However, Boller didn't execute smoothly in the two-minute drill.
He threw three consecutive incompletions after a 23-yard completion to Travis Taylor and Philadelphia was able to run out the clock to secure the win.
"As a quarterback, you want the ball in your hands," Boller said. "Hopefully, we will get that chance again and I will win the game for us." Senior consultant Jim Fassel, the former New York Giants head coach who helped develop Hall of Fame quarterback John Elway, was hired in the off-season to tutor Boller.
Generally, Boller's fundamentals and mechanics appear smoother. Yet, he still seems to regress in stressful situations and occasionally develops happy feet when pressured. Often, Boller's deep passes are off-target or he simply sails them so high that the defensive backs have time to regain the separation created by his receivers.
Fassel has increased his time with Boller, and has been at practice each day this week after generally only being at the training complex on Mondays and Tuesdays.
Billick dismissed the notion of Boller playing with training wheels on while he learns to ride the Ravens' bicycle late in games.
"That's not a restriction I place on Kyle," Billick said. "It's not, 'OK, go out there, play a tight game, but if we're in the fourth quarter, don't win it. We're going to let you do that later in the season.' We don't put restrictions on Kyle.
"There's really not any restrictions on him other than for as long as he's going to be here, and hopefully we'll be together for a long time, there's always going to be a restriction: 'You know what? We don't want you to turn the ball over and don't do anything stupid.' For the most part, he hasn't."
This season, Boller has completed 57.8 percent of his passes for 959 yards, three touchdowns and six interceptions for a 65.3 passer rating. His passer rating ranks him ahead of only Oakland's Kerry Collins (64.6), Miami's Jay Fiedler (64.0) and Cincinnati's Carson Palmer (62.6).
In the fourth quarter, Boller has completed 52.3 percent of his passes for 262 yards, one touchdown, two interceptions and a 59.1 passer rating.
Boller's longest completions are 57, 52 and 47 yards, and Baltimore is gaining 122.3 passing yards a game. He completed 14 of 17 passes in the first half against Philadelphia.
"He's a pretty confident young man," Billick said ."He feels pretty good about how he's performed under the spotlight against outstanding teams in a playoff-caliber atmosphere. We feel pretty good about it, and I know he does."
The Ravens rank 31st in passing net yards per play, 29th in sacks per pass play, 28th in third-down efficiency and 24th in passing percentage of interceptions.
Boller and the entire passing game has suffered from the prolonged absence of Heap (five games) due to a sprained ankle, Lewis' two-game suspension for violating the NFL substance-abuse policy and Ogden's pulled hamstring.
Without the 6-foot-5, 252-pound Heap, the Ravens don't have their leading receiver from the past two seasons.
"Kyle has the ability to be a great quarterback," Taylor said. "He's gaining a comfort zone in the offense and is getting better every week. Kyle is still a very young guy, and he's going to grow. Everybody on this team is excited about him."
Aaron Wilson writes for the Carroll County Times.