When it comes to working with search firms, "when and if" are just as important as "how."

Retained search firms are appropriate vehicles for candidates seeking a "career lateral" - a position whose responsibilities and pay are similar to the job they currently have, says Ann S. Boland, an executive recruiter in the Washington, D.C., area. However, if you've previously performed the role but aren't doing so currently, or if you performed the role only within a different industry or segment, Boland advises approaching target employers on your own rather than through a headhunter. The reason? She answers bluntly on her Web site:

"When companies retain or engage a recruiter, they want someone who 'is there and doing that' (or was very recently). In most cases, recruiters must find a candidate who is currently performing successfully in virtually the same role for another employer."

On the other hand, when a recruiter's fee isn't involved, employers might be open to hiring a candidate who meets some - but not all - of their stated criteria.

The Three Bullets: Experience First

Boland's boiled down retained-search clients' common requirements into a document called The Three Magic Bullets. She explained its themes while addressing a career event organized in Washington by the CFA Institute.

If you try to get a job through a recruiter without having all three of her bullets, you'll be wasting both your time and the recruiter's, Boland says. In her formulation, a presentable candidate's experience and compensation must precisely match the job opening in question, and the candidate must show a stable work history, defined as a minimum two-year tenure in every past job.

How close a match does experience have to be? Apparently, too close to slip your pinky finger between any gaps. Functional expertise, industry experience, and specified qualifications each must match "exactly" with the target job, Boland says. "We've seen specs this tight: chief investment officer who managed growth of a portfolio from $2.5 billion to $3.0 billion, plus has 10 to 15 years experience in the retirement services division of a global mutual fund firm," Boland told the CFA group. "This is why recruiters don't return your call."

As for qualifications: Beyond specifying particular academic degrees and professional certifications, clients typically demand candidates have strong existing relationships with certain defined customer or prospect groups.

Candidates will face resistance if their current or recent compensation history deviates from the target by more than 10 percent in either direction, Boland says.

Stability

The third magic bullet, having a stable work history, rules out any candidate who's held their present role for less than two years or who left any previous job after less than two years. (If you left after a short time to follow a manager to a new job, it's important to say so on your resume. That fact can offset any hesitation over stability.)

Why would anyone want to make a lateral move, switching employers for a similar job at only a modest pay boost? Usually because the new employer is viewed as offering better prospects for career growth. In those cases, working with retained recruiters may make sense, according to Boland.

On the other hand, "If you want a company to bet on your ability to move to the next level, stay where you are a known quantity, or apply directly. Few companies are willing to subsidize a candidate's career progression by hiring them for a position that is a 'stretch' job," she says.