FORT MYERS, FLA. — Johan Santana won at least 15 games a year for the Twins from 2004 to '07, picking up two American League Cy Young Awards along the way. He was a workhorse, a stopper, a dominator, the embodiment of what an ace pitcher should be.

General Manager Terry Ryan was asked which Twins pitchers before Santana were considered true aces among their peers.

"[Frank] Viola, [Jack] Morris, then Santana," Ryan said.

That opinion means the Twins went from 1992 to 2003 without having a candidate for ace designation. And they still are trying to find an ace to replace Santana.

They have a chance to address that need with the No. 2 overall pick in the June 4 amateur draft, a pick they received for their 99-loss 2011 season.

But selecting high comes with no guarantee, because elite starting pitchers are so difficult to find.

The Pittsburgh Pirates have drafted eighth overall or better in nine of the past 11 years. They have taken a pitcher seven times with no luck, although they are hoping last year's No. 1 overall pick, Gerrit Cole, bucks that trend.

Let's be clear about semantics: Every team has a No. 1 starter. Not everyone has an ace. Ryan recently scanned a wall in his office that has every team's roster listed and examined the pitching staffs.

"You got 30 teams," he said. "You go up and down these rosters and find the ones that are legitimate aces. There's 15 maybe. Maybe. We're talking about a select group there."

The locks should include Justin Verlander of division rival Detroit, the Yankees' CC Sabathia, Philadelphia's Roy Halladay and Cliff Lee, San Francisco's Tim Lincecum, Seattle's Felix Hernandez and the Dodgers' Clayton Kershaw -- all Cy Young winners. The Angels' Jered Weaver and Boston's Jon Lester might merit a place on this list, too. After that, it's mostly youngsters with ace stuff trying to master consistency -- pitchers such as Tampa Bay's David Price and Milwaukee's Yovani Gallardo, among others.

The significance of an ace evidences itself in numerous ways over baseball's marathon schedule. An ace stops losing streaks that might otherwise become lengthy. An ace wins big games during the regular season. And an ace gives a team a huge advantage in the postseason.

"To be a No. 1 guy, you have to build a résumé," Ryan said. "You have to be a stopper, Cy Young candidate, capable of winning 15-20 games year in and year out. You have to be reliable, about 70 percent of your starts should be quality starts. Get lefties and righties out. And be a leader.

"And there's just not a lot of guys to meet that criteria."

Close, but no ace

Brad Radke, who went 148-139 in 12 years with the Twins and won 20 games in 1997, was considered a good pitcher over this career, but he lacked overpowering stuff. Ryan said some argued Radke was more of a No. 3 starter than an ace.

Current Twins righthander Carl Pavano has pitched at least 221 innings the past two seasons. But he knows he doesn't fit the criteria to be considered an ace because he relies on defense and execution behind him to get batters out. Pavano, simply put, is not a strikeout pitcher, which nearly all true aces are.

Still, when it comes to separating the good pitchers from the great ones, Pavano believes there are swing moments in games that determine how a season goes from good to great. And how a pitcher can be an ace, if only for a season.

"It comes down to six to 10 pitches a game that cost you big innings," said the 36-year-old Pavano, 106-102 over a major league career that began in 1998. "Like the wrong time to walk someone or pitch around someone, or a couple inches here and there. And execution is a big factor. The guys who do it the most are considered the best."

To succeed in those situations long-term, Twins pitching coach Rick Anderson said he believes that mental makeup sets the great pitchers apart. He spent years watching Santana thrive in those situations before he was traded to the Mets in February 2008.

"Pitching is about how you make adjustments to get deep into games," Anderson said. "You have to have the mentality. I guarantee you that if you talk to some starters they think if they have a quality start [pitch at least six innings, giving up three or fewer earned runs], it's pretty good. You have to have the mentality like, 'I want to go nine innings.' "

Tough to find

It's difficult to trade for an ace or sign one as a free agent -- either a proven ace or an unsigned prospect on the international market. The last time the Twins were even linked to one was Lee, who was traded by Seattle to Texas during the 2010 season. The Twins tried to work out a deal, but some of the players they were willing to talk about in a deal -- catcher Wilson Ramos, for one -- were either injured or struggling.

"Every year I go out and see all the top guys in the draft, all the international guys," said Mike Radcliff, Twins senior vice president in charge of player personnel. "I'm aware of free agents and all the guys who are available to be acquired on the major league market. And there's not a No. 1 guy available every year.

"If you're not picking at the very top of the draft, or if you're not willing to spend a whole bunch of money in the international market, if you're not willing to spend $100 million like the big dogs get in the free-agent market, then you are not going to get one."

Just how much teams are willing to pay for a potential ace was evident this offseason when the Rangers committed $108 million for Japanese righthander Yu Darvish, a figure that includes a $52 million posting fee to Darvish's former team.

The Twins are looking at prospects at all positions, but they are very aware of the opportunity to select a front-line starter. Power pitchers normally don't last long in the draft, so this is their chance. They were on hand this year when California prep pitcher Lucas Giolito hit 100 miles per hour on the radar gun, and they were there the night he injured his elbow earlier this month and clouded his draft status.

Recently, they have been scouting University of San Francisco righthander Kyle Zimmer, who throws in the mid-90s and is moving up the charts.

There are excellent position players available such as Arizona State shortstop Deven Marrero and Georgia prep outfielder Byron Buxton, but the lure of landing a top pitching prospect and all that can mean might be too good to pass up.

"We're picking high, are you kidding me?" Radcliff said. "We're bearing down on all the top pitchers. Hopefully that's what we'll try to get."