They began playing pitch and catch late last March, a young quarterback and his favorite receiver going out onto the practice field every day to work on patterns, to perfect their timing, to get a feel for each other's idiosyncrasies. Sometimes, other players joined them, but many times, there were no defenders, no coaches barking orders, just Peyton Manning dropping back and throwing and Marvin Harrison dashing toward a cut and catching.

As the NFL season heads into the homestretch, not much has changed. Manning to Harrison has become one of the most feared passing combinations in the league this season, a major reason--along with rookie running back Edgerrin James--the Indianapolis Colts are 8-2 and tied for first place in the AFC East as they prepare to host the suddenly resurgent New York Jets Sunday at RCA Dome.

"We took one play a day from every angle," Manning said in a recent interview about his offseason routine with Harrison. "We went out there and said, 'Okay, we're going to throw 18-yard comeback routes.' Then we did it against every situation, any kind of look we could get. Now, during the season, when we see different looks, we can go, 'Hey, remember blitz, 18-yard comeback. Break it off at 15.' "

Said Harrison: "Last year against the Patriots, me and Peyton messed up on a crossing pattern near the end of a game. [General Manager] Bill Polian came up and said, 'Don't worry, you'll work on it in the offseason and it won't happen next year.' He was right. Now we know what each of us is doing before we do it, just because we practiced it so much. It might just be a look from Peyton, but we know what to do."

Manning is the AFC's leading passer, completing 60 percent of his throws, with 20 touchdown passes. The Colts are tied with St. Louis for the No. 1 offense in the NFL. Harrison leads the league in three categories--with 69 receptions for 1,056 yards and 12 touchdowns. James leads the league with 1,420 all-purpose yards--1,006 rushing, 414 receiving--and the Colts look to have an offense that will keep them in contention until free agency or the salary cap do them part.

It all begins with Manning, the son of former NFL quarterback Archie Manning and the first overall selection out of Tennessee in the 1998 draft. He's more than lived up to his reputation as a cerebral student of the game with a lively arm and a fabulous feel for all the subtle nuances his position requires. Usually it takes a quarterback four to five years to get The Big Picture. Manning already is creating masterpieces, far sooner than Polian or Coach Jim Mora thought was humanly possible.

"I did not expect Peyton to be playing as well as he has in his second year," Mora said. "It's the toughest position in sports. To me, what he's doing is absolutely incredible. He's a special person and a special player. We've done it probably quicker than anyone anticipated, certainly than I anticipated.

"He's matured beyond anything people thought he could. I've also never been around a quarterback-receiver pair that works as hard as they do, whether it's in meetings, talking to each other, working out together. Before a game they'll be the first guys on the field. They're both talented athletes, capable of making big plays, and our coaches have done a great job designing the offense to take advantage of their skills."

Polian made the decision to select Manning ahead of Washington State's Ryan Leaf, taken by San Diego with the second overall selection. Leaf had the stronger arm, but has been a bust for the Chargers, on and off the field.

Polian said he believes "Leaf still has a chance to turn it around and be a good quarterback in this league." Nevertheless, his decision to bet the future of the franchise on Manning, as well as surrounding him with more talent on both sides of the ball, has made the Colts an instant playoff contender with potential for long-term staying power.

"Peyton is special," Polian said. "To try to even think that other rookies would match up to what he's done is a disservice to the other players because this guy is unique. He was the front-runner going in [to the '98 draft] and the front-runner going out. We did our homework, which was the prudent thing to do."

Manning struggled in his rookie season, just as Mora and Polian expected.

But by midseason of that first year, he looked far more comfortable in the pocket, was learning to read defenses and clearly was no longer having problems adjusting to the speed of the game.

He also continued to exhibit the sort of manic work ethic that had made him a legend at Tennessee--hours in the film room studying opponents, studying himself, and hours more on the practice field and the weight room to prepare himself physically.

"From the middle of the ['98] season until the end, I thought I found a comfort level and had a good feel for things," Manning said. "It was hard to lose that much, but my father gave me good advice. He told me the NFL is a marathon, not a sprint. As a quarterback, you want to get in that comfort zone right away, but it does take time.

"The biggest thing I've improved this year is my discipline and my decision making. When things aren't there, I'm throwing it away or maybe improvising a little bit. I'm making quicker decisions and I feel like I'm at my best when I'm making quicker decisions. I'm using the experience I gained last year to my advantage this year."

His teammates insist they thought Manning was the real deal right from the start.

"From the first day, it was his huddle and his offense," said offensive tackle Adam Meadows. "It might be a cliche, but he acted like a 10-year veteran and had everyone's eyes on him. As far as I'm concerned, Peyton is the meal ticket. Anyone who works as hard as he does gets respect."

His quarterback coach, Bruce Arians, said Manning's knowledge of the position also has taken a quantum leap since his rookie season.

"There are throws he couldn't make [last season], either not understanding where the ball wanted to go so his body wouldn't allow him to, to where his eyes would take his hands and feet to places they didn't need to be," Arians said.

"As a quarterback, your eyes lead your hands and feet, so they'll get you out of whack sometimes when you're throwing to your right but you're looking to your left and your shoulders are not in good throwing position. He's worked really hard to keep his body in throwing position when he wants to look people off or move his eyes around the field."

Though the Colts finished 3-13 last year, Manning took every snap in practice and in the games. He threw 575 passes, piled up 3,739 yards and 26 touchdowns on the way to setting five league rookie passing records.

After the season, Colts offensive coordinator Tom Moore insisted that Manning take at least a month off before he come back to the team's facility in suburban Indianapolis to begin preparing for the '99 season. He didn't want Manning to burn out, and so the kid quarterback went duck hunting with his father, then spent a week in Hawaii during the Pro Bowl. But he also couldn't wait to get back to the Colts' facility to play a little pitch and catch with Harrison.

"Peyton is a competitor," Harrison said. "He wants to win, and I want to win. Things are going well for us right now, but we know we can still get better, too. We put a lot of work in together in the offseason, and it's all paying off for us right now."