Coach Ken Whisenhunt has already pulled off the impossible in Arizona, helping the Cardinals go from perennial losers to the Super Bowl.

Recent history says his next challenge will be even tougher: coaxing sustained success from a quarterback who entered the NFL as a second-round draft choice. The chart below tells you what you need to know.

The Cardinals' long-awaited play for Kevin Kolb is finally becoming a reality, with ESPN's John Clayton saying Arizona will send one-time Pro Bowl cornerback Dominique Rodgers-Cromartie and a second-round draft choice to Philadelphia.

The price Arizona pays is high and also highly overrated. If the Cardinals are right on Kolb, the price won't matter. If they're wrong, the damage done will far outweigh a 185-pound cornerback and the draft pick Arizona included with the deal.

Whisenhunt, whose contract runs through 2013, could be betting his job on Kolb, whose new deal will run through 2016 and pay him as much as $63 million.

That is OK.

Not landing a quarterback wasn't an option. The Cardinals needed to make a move for one, and if they valued Kolb the way this trade says they valued him, they needed to act.

Restoring clarity and hope to the position gives the Cardinals a shot at re-signing Larry Fitzgerald, whose contract voids after this season. Arizona has already lost too many key players in recent seasons: Karlos Dansby, Antrel Rolle and Anquan Boldin are but a few. Losing Fitzgerald following another quarterback train wreck would threaten to set back the organization to its pre-Whisenhunt days. Phoenix is not Green Bay or Pittsburgh or even Seattle and San Francisco on the fan loyalty front.

Landing a quarterback with promise puts Arizona back into the NFC West race. Go ahead and laugh, but if the Seattle Seahawks could beat the defending Super Bowl champs as 7-9 division winners last season, the Cardinals can keep a straight face liking their chances with Kolb behind center and Whisenhunt's 4-2 postseason record on their side.

We'll find out more about whether Whisenhunt can identify and develop talent at the position. Was he a driving force behind Ben Roethlisberger's historic rookie season in Pittsburgh, or mostly a beneficiary of it? Was he pivotal in restoring Kurt Warner's career by persuading Warner to reform his Mike Martz-coached penchant for the daring? Or did Whisenhunt luck into a Hall of Famer, with former coordinator Todd Haley taking the lead internally?

These questions may not have clear yes-or-no answers. But the narrative gets written in Whisenhunt's favor if Kolb, a second-round choice of the Eagles in 2007, becomes the next Drew Brees. As the chart shows, Brees is one of three second-round quarterbacks since 1995 to earn Pro Bowl acclaim. The other two, Jake Plummer and Kordell Stewart, had their moments during ultimately unsatisfying careers.

Kolb is just 26 years old. If he were a surefire franchise quarterback, the Eagles never would have traded him. They would have signed Kolb to a long-term deal even before Michael Vick emerged as the best option for them. Instead, they parlayed the 36th player drafted in 2007 into the 16th player chosen in 2008, plus a second-rounder.

The Eagles got the better of this deal based on what we know right now. The Cardinals could come out well ahead based on what they think.

They need to be right on this one.

1995-2010 Second-round QBs: Most games played

As a bonus, and because a Charlie Whitehurst mention is always good for a few extra comments, let's also take a quick look at third-round quarterbacks drafted since 1995, arranged by team:

• Arizona: Stoney Case, Josh McCown

• Atlanta: Matt Schaub

• Baltimore: Chris Redman

• Buffalo: Trent Edwards

• Cleveland: Eric Zeier, Charlie Frye and Colt McCoy

• Denver: Brian Griese

• Houston: Dave Ragone

• Jacksonville: Jonathan Quinn

• Kansas City: Brodie Croyle

• New England: Kevin O'Connell

• Oakland: Andrew Walter

• Philadelphia: Bobby Hoying

• San Diego: Charlie Whitehurst

• San Francisco: Giovanni Carmazzi

• Seattle: Brock Huard, David Greene

• Tampa Bay: Chris Simms

Schaub and Whitehurst, like Kolb, were among those who wound up commanding value in the trade market.