Time provides the ultimate test of any investment strategy. When that strategy is long-term, the wait can seem endless.

No matter when you boarded the precious-metals train, or even if you're still waiting at the station, Fools participating in the nine-year-old bull market for precious metals will require a steady hand and an iron constitution. If you're just getting started now, you will find supportive fellow investors at Motley Fool CAPS -- like blogger binve -- who are happy to share their experiences.

Size matters
As I constructed my own approach to the sector years ago, I became convinced that the largest-scale miners could find it challenging to replace or sustain their production volumes in a world with diminishing new discoveries. Although I have consistently recognized Newmont Gold (NYSE:NEM) as a high-quality titan of the gold mining scene, my CAPS pitch from January 2008 conveys my preference for the mid-tier space:

I have owned Newmont and several other large-scale miners for a few years now, and they've done extremely well. […] I foresee the mid-tier miners outperforming the big guys for the next couple of years. […] I own a basket of mid-tier and juniors, many of which will be purchased by the Newmonts of the world. If I end up owning more Newmont next year because they purchase IamGold (IAG) or Gammon Gold, then so be it.

As it turned out, the latter half of 2008 saw the entire business world crippled by frozen credit and paralyzed by panic, and the precious-metals sector plagued by a monster correction. The timeline for an inevitable consolidation trend was delayed, until Newmont sprang to life with a huge deal for the Boddington mine in Australia.

While recognizing the greater upside potential of smaller operators relative to their large-scale kin, it is necessary to consider the relative risks as well. The universe of junior miners, a classification that also includes exploration-stage companies, is vast and varied in quality. This Fool finds the greatest compromise between potential risk and reward within the universe of mid-tier miners.

Standing out … in the middle of the road
Although I focus much of my attention upon quintessential intermediate producers like Yamana Gold (NYSE:AUY), several quality gold and silver miners populate this mid-tier space. Prompted in part by a rush of recent developments that merit analysis, I bring the following five miners to your Foolish attention:

  • Eldorado Gold (AMEX:EGO) is one of the longer-running holdings in my own precious-metals basket. The company's recent move to acquire Australia's Sino Gold leaves Eldorado the premier choice for Western investors seeking exposure to Chinese gold production.
  • Gammon Gold (NYSE:GRS) is another longtime favorite that is gaining momentum, now that an expansion of the flagship Ocampo mine has achieved commercial production. The company raised $100 million this week in bought-deal financing, and reiterated improved, low-cost production targets. Creating value with the drill, Gammon also encountered a bonanza-grade strike of 318 grams-per-tonne gold within the Ocampo area.
  • IAMGOLD (NYSE:IAG) has remained in an impressive growth spurt since it merged with Cambior in 2006, and the company's bold move to cancel royalty claims during the worst phase of the correction made IAMGOLD a lean, mean cost-cutting machine. IAMGOLD is targeting robust production growth from nearly 1 million ounces to 1.8 million ounces by 2012, and watching for accretive acquisitions.
  • Coeur d'Alene Mines (NYSE:CDE) is the turnaround story of 2009. After gazing into the abyss of potential failure, Coeur shares have multiplied more than six times from their split-adjusted low of $3.60 recorded last November. With the Kensington gold mine back on track, and on the heels of two world-class silver mine launches, Coeur is now looking to expand ore-processing activity at its Rochester mine in Nevada for an additional 2.9 million ounces of annual silver production.
  • Taseko Mines (AMEX:TGB) is a primary copper producer with a relatively puny market capitalization, so perhaps it doesn't technically belong on this list. Although Taseko just revealed a hiccup in ore concentrations during the third quarter, the company mines enough low-cost copper at Gibraltar to ensure a stable and reliable revenue stream. I consider Taseko one of the greater values in the mining space, and I believe that the market continues to price shares as though the Prosperity property -- with its 4.7 million ounces of gold reserves and 2 billion pounds of copper -- does not exist.

With gold yet again reaching new heights above $1,050 per ounce, and venerable voices such as Jim Rogers urging caution (despite forecasting much higher long-term prices), I am not advocating an abrupt move into new positions at these levels. On the other hand, I consider it more important to have some exposure to the sector than to get the timing perfectly right. Whatever Fools decide, I hope the above discussion helps to inform due diligence.