Oh to be 27 again.

It is the ripe ol' age in Fantasy Baseball circles -- when boys become men and, consequently, when they become very rich men in the free-agent market.

Case in point: Carlos Beltran, 2005's 27-year-old deluxe in Fantasy leagues and the prized signee of the Mets to the tune of seven years and $119 million.

It has long been the belief age 27 is the beginning of a player's prime. The best proof is in the dollars.

The dollars Beltran received this offseason came before his 27th birthday. As did the 10-year, $250 million deal Alex Rodriguez signed back in December of 2000, which is still by far the richest contract in major-league history in both total and average dollars. Those two rank Nos. 1a and 1b in CBS SportsLine.com's Preseason Top 300.

Not buying the hype over those big-ticket deals? How about the proof is in the stats, then.

At age 27:

• A-Rod hit a career-high 57 homers -- with a career-high 142 RBI and .623 slugging percentage.
• Vladimir Guerrero posted a career-best strikeout-to-walk rate (53 to 63), which led to his big-time free-agent contract with the Angels.
• Manny Ramirez drove in a career-high 165 runs, scoring a career-high 131 times and posted his best single-season average, on-base percentage and slugging percentage at that point in his career.
• Bobby Abreu hit a career-high 31 homers, drove in a career-high 110 runs and scored a career-high 118 times.
• Miguel Tejada, who was 27 on opening day last season, drove in a career-high 150 runs, hit a career-high 34 homers and set career bests across the board in average, on-base, slugging and OPS.
• Barry Bonds drove in 116 runs (a career high at the time) and posted a .410 on-base percentage (also a career high at the time).
• Alfonso Soriano hit 38 homers, just one off his career high, and posted the highest on-base and stolen-base percentages of his career en route to becoming rated one of the top Fantasy picks last spring.

All of those players' age-27 breakthroughs are significant, particularly in Fantasy circles. They represent 70 percent of the top 10 players in our Top 300.

Potential five-tool, five-category star Carlos Beltran is entering his golden age-27 season. (Getty Images)

The missing three? They have yet to take the field in their glorious age-27 season: Beltran (2005), Albert Pujols (2007) and Johan Santana (2006).

The correlation runs much deeper than that, we assure you. Space limitations won't let us go into it completely here, but trust us.

Buy into the age-27 phenomenon. It isn't a mirage created by clever player agents. It truly is the golden year for players to break out.

Beltran, of course, is the reason we are doing this feature to help you with your 2005 Fantasy draft preparation. He is rated a very-close No. 2 to A-Rod in the Top 300 -- the uncertainty of Shea Stadium and the Mets' effect(s) being the reason(s) he wasn't No. 1.

Some will justifiably rate him No. 1, especially when you consider his five-category potential and the fact the age-27 phenomenon is on his side.

Last season's big Fantasy breakouts are more great examples of it:

• Tejada, with his amazing 150 RBI at the shortstop position.
• Michael Young, who emerged as a huge breakout and a stud Fantasy shortstop as A-Rod's replacement, reaching career highs in runs, hits, doubles, triples, homers, RBI, walks, average, on-base, slugging, OPS, games and at-bats.
• Brad Lidge, who set a major-league relief record with 157 strikeouts and emerged as a stud closer.
• Carlos Lee, who reached career highs in runs, doubles, homers, average, on-base, slugging and OPS.
• Lyle Overbay, who was a huge surprise in his first full season, setting career highs in every category.
• Lew Ford, who came from off the Fantasy free-agent pile as a steadily productive DH in Minnesota.
• Craig Wilson, 2004's super sleeper as a catcher eligible, who would up setting career highs in: games, at-bats, runs, hits, doubles, triples, homers and walks.
• Ramon Hernandez, who posted career highs in average, on-base and slugging percentages.
• Ryan Drese, who emerged as a 14-game winner and helped lead the Rangers as one of the surprise teams in the AL.
• Michael Barrett, who posted career highs in games, runs, hits, triples, homers, RBI, average, on-base, slugging and OPS.

We could go on and on, but you get the picture.

Our Draft Preview provides the complete rankings of last year's 27-year-olds overall and by position. It will read to you like a Fantasy breakthrough-players-of-the-year list.

We don't make this stuff up. You will want to study the status of this season's 27-year-olds. It is the place where 2005's best sleepers will reside.

There are certain to be some big-time breakouts, and they will result when preparation meets opportunity meets a birthday cake with 27 candles on it.

Below is the 2005 Preseason All-27 Team. Granted some of them you already knew would be valuable in Fantasy leagues, but we also provide the All-27 Sleeper Team, players who could see huge bumps in value during the season.