"He's a complete pitching coach," said manager Tony La Russa, "in the sense that whatever your issue is, he can deal with it."
The Cardinals are looking for Duncan to do it again this year with a rotation that has been drastically renovated. Along with youngsters Adam Wainwright and Anthony Reyes, St. Louis is counting on two pitchers who might be considered classic Duncan projects.
Kip Wells, once a frontline starter for the Pirates, has struggled with injuries and ineffectiveness for three seasons. Braden Looper has been a reliever for the entirety of his big-league career. Duncan fully expects that they will both be success stories at the end of the year.
"There are a lot of ways to pitch effectively at the Major League level," Duncan said. "You have to look and identify things that [a] guy can do to be an effective pitcher. Now, can he do them consistently? If you think he can, or he can gain the ability to do it consistently, then they're worth taking a shot on -- provided they're willing to work, they're good competitors and they're of good character."
Duncan and the Cardinals believe all of those qualifiers apply to Looper and Wells. So they believe they'll have two very good starting pitchers in Looper and Wells.
Are there other, more specific traits that make them "Duncan types," though? Duncan himself says not really.
"The common thread of the people you're talking about," he said, "is that they're all good competitors, good character and maybe not superstar ability, but certainly the ability to get Major League hitters out."
A few qualities do pop up again and again, however. Duncan relishes pitchers who throw sinking fastballs and throw strikes. A power arm isn't a must, but it certainly doesn't hurt. Mostly, the pitchers must be willing to buy into the plan.
"I was stubborn as a young kid, felt like I could throw the ball by everybody, or throw sinkers and break bats or whatever," said Looper. "But now I enjoy a different aspect of it -- the pitching part of it. Sink, cut, split. Slider first pitch, or whatever it is. That has been the most fun part of it."
And that may be one key to Duncan's run of success with veterans. To get the most out of a coach, players must be willing to listen to that coach. They must know what to listen for. And they must be willing and able to act on the suggestions.
"He doesn't say a lot, but when he does have something to say, it's definitely worth listening to," said Cal Eldred, who came out of retirement to pitch three years in relief for St. Louis. "And as soon as a player figures that out, the better. There's a lot of guys who get afraid when a coach doesn't talk to them. Sometimes that's not all that bad a thing. Dunc, he knows how to explain to pitchers what their responsibility is."
Duncan was the first person to suggest that Looper might make a quality starter, and it wasn't only a need-based assessment. He believes Looper can be more than just a body in a rotation that needs pitchers. He expects the right-hander to be a real contributor. He's always admired Wells' talent and competitiveness.
Those assessments go a long way with the Cardinals.
"He gets the ultimate confidence and respect," La Russa said.
So now Looper is refining his offerings and his mentality in order to try to be a successful starter. And Wells is looking to reach the level at which he pitched in 2002 and 2003 with the Pirates. They'll both be getting their first taste of starting for Duncan. They'll see the reams of data, and go through the intense meetings.
When Looper pitched in relief for the Cards, he got only a partial taste of all of that. Now that he'll be trying to get the same hitters out three and four times a game, the plan will be individualized more to his skills and strengths.
Wells, Looper and Eldred all say that individualization is a big part of Duncan's success. There's a plan, but it's attenuated to what the pitcher does well. Duncan identifies a pitcher's strengths, then helps maximize them.
"Obviously, you've got to improve on certain areas, but don't try to reinvent yourself," Wells said. "Don't try to be somebody you're not. And then, when you go out there, they have the best game plan to get you to produce as well as you can over the course of each game."
Asked for a specific improvement he made under Duncan, Eldred points to a very small one. A starter for his whole career, Eldred made the switch to throwing exclusively from the stretch once he began working as a reliever. It helped make his delivery more consistent, and his command more reliable.
"What his system is," said Eldred, "is that he shows you what your weapons are and shows you how to use them."
It's simple, but so very successful. And it's no coincidence that La Russa, the third-winningest manager in baseball history, has had Duncan by his side for 25 consecutive seasons.
They've worked together since 1983. In their first season together, the White Sox won 99 games, taking the American League West, and La Marr Hoyt won 24 games and the Cy Young Award. Since then it's been a pattern of success. Pitchers hook up with Duncan, La Russa, et al, and enjoy some of their finest seasons.
Hall of Famer Tom Seaver enjoyed a late renaissance with the Duncan-La Russa White Sox. Dave Stewart emerged as an ace, and one of the most feared pitchers of his era, in the first season in Oakland. Scott Sanderson re-emerged from a long dry spell for one fine year in Oakland.
Kent Bottenfield, who won 46 games in his entire big-league career, picked up 18 of those in his only full year as a member of the Cardinals rotation. Woody Williams, acquired in a waiver deal in August 2001, became an All-Star as a Cardinal. Most recently, it was Jeff Suppan and Jeff Weaver emerging as big-game winners for the 2006 World Series champions.
Not that it's done without help. Quite the contrary.
Bullpen coach Marty Mason helps with game planning and mechanical adjustments, and the catchers implement those plans on the field. The training staff helps get injured pitchers back on the mound and keeps healthy pitchers healthy. The front office identifies pitchers who may not have lived up to what they can accomplish.
"What you have in Dunc is really special," Eldred said. "Then what you have in Marty standing next to him is special. And then you have strength and conditioning with Pete [Prinzi]. You've got preparation with the training staff. And then you've got catchers -- if you don't have good catchers, you don't have a good team."
Duncan, himself a former catcher, leans heavily on his receivers. They must know and understand the plan, but they can't be robots. They need to be able to think on their feet -- or in a crouch, more accurately.
"They understand what we're trying to do," Duncan said. "And they put as much effort into being ready to implement a plan of attack as the pitchers do.
"It's taking a pitcher and being able to use him to his best advantage -- not letting him get beat on something that he's not proficient at doing. The way you're going to use Wells is going to be different than the way you use Anthony Reyes. You've got to understand that each guy has to take his style and apply it to the information we have."
Will Looper and Wells be the next guys to fuse talent with that information? Will they be the next to make the Cards' front office look brilliant for acquiring them, and Duncan look like a wizard for two more successful reinventions?
The record says it's more likely than not.