After the season ended each year, Peyton Manning would walk into Tony Dungy's office clutching a notebook with a list of his perceived weaknesses and things to work on. Last season, there was no meeting. Instead, Dungy called Manning to tell him he was retiring as the coach. But there was still the list. And because it appeared that the only offensive coordinator and offensive line coach Manning had known in the pros were retiring too, the list was longer than ever. 'This has been a different type of year,' Manning said Wednesday. 'This year was really curious.' It may be Manning's finest. With two of his top three wide receivers from last season gone (Marvin Harrison into the netherworld of old, unwanted players; Anthony Gonzalez to injury), and with a rookie (Austin Collie) and a second-year player (Pierre Garcon) in their spots, Manning has completed 70.6 percent of his passes. If he finishes the season that high, he would have the highest completion percentage of his career and in NFL history, eking past Ken Anderson's record of 70.55 in 1982. Halfway through the season, Manning is on a pace to surpass Dan Marino's record for most passing yards in a season (5,084, in 1984). He would shatter his own personal bests for attempts, completions and yards per game. He almost surely will not approach his 49-touchdown season of 2004, but his production raises a question as the Indianapolis Colts (8-0) prepare for their annual midseason game Sunday against the New England Patriots and Tom Brady, the only current player who is truly Manning's peer: Will Manning, at 33, after three league most valuable player awards and a dozen years in the NFL, ever reach his ceiling? 'I don't think so,' said tight end Dallas Clark, who leads the Colts with 60 receptions. 'He is always trying to find an edge. I think he thinks anything is possible.' In this case, it may be. Manning is a famous gym rat, renowned for his film study and for hewing to a routine in his pregame warm-up throws. Dungy, now an NBC analyst, said Manning was such a creature of habit that when he started slowly in the first five games of the 2008 season, he was not thrown off by the surgery on the bursa sac of his knee. The problem was that Manning's meticulous off-season throwing regimen had been interrupted: instead of throwing the prescribed number of passes by July 1, he had not thrown any, Dungy said. The Colts have changed remarkably little since Manning arrived, with the coaching staff, the front office and even much of the roster intact, allowing Manning to fine-tune the complex offense bit by bit, with each of his annual to-do lists. It makes Manning perhaps the NFL's greatest student, but it might not have prepared him for the jarring adjustments this season has demanded. For a while, Manning conceded, he did not know what to expect. 'I knew we had to address the wide receiver position somehow, but I thought it would be by committee,' Manning said. 'It took a different turn when Gonzalez got hurt. So many new guys, you just don't know. It's not easy because we don't really allow you to be a rookie. Dungy didn't do rookie singing, didn't want anybody shaving heads. His reason was, 'I want to get them as comfortable as they can because they're going to have to play for us.' We're not very patient with them. I do think they feel more comfortable.' That's a bad sign for opposing defenses, but for an early indicator of what they're in for, perhaps opponents should follow more closely Manning's demeanor during the summer. Peyton's father, Archie, said that Peyton was in a great mood when he came home to visit his parents. 'It was because he was healthy,' Archie Manning said. 'It wasn't taken away from him, but it almost was. You almost have to experience that, or be shut down, to be able to appreciate it. He was drilling like he's always been.' By the summer, Manning had spent dozens of extra hours with Collie, a fourth-round pick who may be the next Brandon Stokley in the slot, and Garcon, the sixth-round project from Mount Union, an NCAA Division III power, who was forced into the starting lineup after Gonzalez's injury in the season opener. These private Manning tutorials are part of the Colts' fast-track assimilation process. The Colts do not scale down their offense, they demand precision no matter who is lined up. In 2002, Manning worked on becoming more comfortable throwing to the left, where a young receiver, Reggie Wayne, lined up opposite Manning's preferred target, Harrison, who was always on the right. For the past few years, with Harrison's career on the wane, Manning focused on preparing Gonzalez to take over. With Garcon, the extra work began in May and started early each morning with the mind-numbing repetition of running routes and going through calls and signals. 'He said: 'Be ready because you're going to play a lot. We need you to know what you're doing,'' Garcon said. 'We were just trying to get on the same page.' They did, quickly. In Week 2, Garcon's first career start, he caught a screen pass against an all-out blitz, slipped past some tacklers and sprinted 48 yards for the winning touchdown in a game in which the Miami Dolphins had the ball for 45 minutes. Collie's 32 receptions lead all NFL rookies. Clark said: 'It's the same thing he's done to me and Gonzo. It's a lot of redos and run it again. It's a way of throwing away everything you've done in the past. This is how it's done, and you've got to learn it. You've got to adjust to the system. Guys that can do that can make big plays.' So far, Collie (356 yards receiving, 4 touchdowns) and Garcon (23 receptions, 353 yards, 2 touchdowns) have made them, although in the Colts' pass-heavy attack Manning is leaning more than ever on Clark (60 receptions, 703 yards, 3 touchdowns), who has never caught more than 77 passes in a season. The Patriots, though, will present a different test for the new faces, one that even Manning may be unable to prepare them for. In a previous game in the rivalry, safety Rodney Harrison and cornerback Ty Law switched positions, confusing even Dungy. In another, the Patriots, who had been an almost exclusively 3-4 defense, played practically nothing but a 4-3 against the Colts. Still, Dungy says that Manning, while a stickler for his routine, has been enlivened by the uncertainties of this season, even though the coordinator Tom Moore and the line coach Howard Mudd ended up staying. 'I think he's a little more focused, realizing he needs to work those young receivers in there,' Dungy said. 'I think that gave him a little motivation. He will never be mentally lazy.' And in a few months, whenever the Colts' season ends, Manning will go back to his film room with his notebook, trying to improve again on what seems unstoppable. 'It's hard for me to say,' Manning said about whether he was playing better than ever. 'We've had some other years. I'd love to be able to tell you that at the end of the season.' 