ORLANDO, Fla. -- After utility man Osvaldo Virgil became the first Dominican to play in Major League Baseball in 1956, it took 30 years for the Caribbean island to place 100 players in the world's top baseball league. During the next three decades that number would multiply by six, driven by academies built to exploit what seems to be an inexhaustible gold mine of talent.

The construction of baseball academies throughout a large part of the Dominican Republic -- an experiment that got a modest start in the late 1970s and early 1980s -- really took shape with the opening of the Dodgers' Campo Las Palmas in March 1987. That build was the catalyst for today's Dominican baseball industry.

Today, all 30 big league teams have academies that, including the bonuses awarded to new prospects, inject an average of more than $90 million a year into the local economy, according to estimates by the MLB office in Santo Domingo.

According to Rafael Pérez, MLB director of Dominican operations, in the past 10 years 15 academies have been built at an average cost of $4 million each. The more modern and luxurious academies have cost $6 million to $8.5 million, a large sum compared to the $785,000 it cost to build Campo Las Palmas.

"Right now all the teams have moved or are in the process of moving to new facilities. The Dodgers are renovating Campo Las Palmas, Philadelphia and Minnesota are finishing their own academies, and St. Louis will be moving into a new facility built with private investment," Pérez said.

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"The impact of the academies has been huge. In the Dominican Republic, 450-500 players are being signed a year, and one of the reasons for this is that each team has optimal conditions to develop them."

According to a Major League Baseball study from 2003 and updated in 2014, the U.S. baseball industry, including a portion of the salaries earned by Dominican players on 40-man rosters, contributes $150-170 million to the island's economy. In construction and operations alone, the academies generate thousands of direct and indirect jobs.

Not including the players, each major league academy in the Dominican Republic has an average of 30 regular employees.

Years before the Dodgers, the Toronto Blue Jays and St. Louis Cardinals tried out the idea of having dedicated spaces to train and house their prospects in the Dominican Republic, but the premises didn't have the facilities Dodgers president Peter O'Malley required for Campo Las Palmas when he green-lighted the project for Rafael Avila, who at the time was supervisor of Dominican operations for the National League team.

"O'Malley told me if we were going to do something, we were going to do it well," Avila told ESPNDeportes.com from his home in Miami.

Pedro Martinez Jed Jacobsohn/Getty Images

"The Dodgers wanted a place where players would have the right atmosphere to develop their athletic abilities but also where they would be safe, where they could learn about the things they would face in the U.S. and where they would feel at home," Avila added.

Built on a large expanse of land measuring 96,000 square meters in Guerra, a town in the province of Santo Domingo, to the east of the capital, Campo Las Palmas revolutionized the way Dominican talent was harnessed and developed. The academy is equipped with two fields, two half fields to train infielders, a gymnasium, a cafeteria, a game room, a study and a dorm accommodating up to 100 players and a farm that previously produced all the food consumed on site.

This is the place that produced pitcher Pedro Martínez, who will be inducted into the Baseball Hall of Fame in Cooperstown, New York, in July, and his brothers Ramón and Jesús. It produced pitchers Pedro Astacio and Juan Guzmán; infielders Adrián Beltré, José Offerman and José Vizcaíno; and outfielder Raúl Mondesí, among many others.

"The first time I got to Campo Las Palmas I thought I was in baseball heaven. I had never seen anything like that in my life. Everything in order and clean and completely level fields," recounted Mondesí, who was the National League Rookie of the Year in 1994, a two-time Golden Glove winner, and who made the 30-30 club twice during his 13-year career in the majors.

After retiring from baseball, Mondesí entered politics and is currently in his second consecutive term as mayor of San Cristóbal, his home city in the south of the Dominican Republic.

As academy construction increased, the number of Dominican players in Major League Baseball skyrocketed. From 110 in 1987, the number jumped to 309 in 2000, 503 in 2009, and 640 when infielder Wilmer Difó made his debut with the Washington Nationals this past May 19. With a few rare exceptions, the vast majority of the 500 Dominican players who have come to MLB since 1991 have been trained at the island's academies.

Pedro Martínez, who was elected to the Hall of Fame with 91.1 percent of all possible votes, won three Cy Young Awards and 219 games during an All-Star career with the Dodgers, Expos, Red Sox, Mets, Yankees and Phillies. His older brother, Ramón, won 135 games in 14 seasons with the Dodgers, Red Sox and Pirates.

Jed Jacobsohn/Getty Images

Outfielder Vladimir Guerrero and third baseman Adrián Beltré will be strong candidates for the Hall of Fame once they're eligible. A nine-time All-Star and 2004 American League MVP, Guerrero will be on the Cooperstown ballot in December 2016. Beltré is still active.

Of the 30 academies, 27 are located in the east of the Dominican Republic in a corridor located between resort town Boca Chica and San Pedro Macorís. Only Oakland and St. Louis (in Villa Mella) and San Diego (in San Cristóbal) have academies located outside the area.

"Regular people will never be able to understand how important the academies have been in training players like Pedro Martínez, to give an example," said Eleodoro Arias, the pitching coach who trained the Martínez brothers and most of the Latin American pitchers to come out of the Dodgers' system in the past two decades.

"It was a lot of extra work on regular-season workdays and during the offseason made possible by having the right place, which helped develop Pedro and many others," Arias added.

"The academies have been critical to increasing the number of players that get signed, accelerating and improving their development and increasing the percentage who achieve the goal of playing in the majors. In baseball, it's all about numbers, and the academies' numbers are extremely positive," Pérez said.

The academies not only prepare the players, who are generally 17 to 19 years old, in technique, but they've also implemented educational programs that offer English classes, leadership workshops, anger and stress management, etiquette and protocol, basic American culture and formal education.

Basically, the academies offer the players the tools to develop themselves in the future, even if they don't achieve their goal of playing in the majors. The numbers are sobering: Less than 3 percent of prospects who were signed in the Dominican Republic in 2006 made it to the big leagues, compared to 11.5 percent of those signed in the United States during the same period, according to numbers published by Mother Jones magazine in 2013.

Industry data obtained by ESPNDeportes.com shows that only 3-5 percent of players signed in the Dominican Republic make it to the majors, compared to 11-17 percent of those signed in the United States. Fifty percent of players who reach the major leagues come from North American universities, 25 percent come straight out of high school and 25 percent are from the international market.

Dominican players who reach the majors spend approximately five to seven years in the minors first. But not everything is rosy. The 2011 death of 18-year-old Nationals prospect Yewri Guillén brought attention to the lack of adequate medical treatment at many Dominican academies.

Dominican doctors initially reported that Guillén died from bacterial meningitis, but later the MLB medical committee announced that the cause of death was a brain infection caused by an aggressive case of sinusitis. In addition, the committee concluded that the Nationals took appropriate steps to ensure proper medical care was given and that protocol was followed in order to avoid a meningitis outbreak.

However, a Mother Jones report in 2013 stated the Nationals didn't have the authorized medical personnel at their academy to properly treat Guillén's condition, and that 21 of the 30 MLB teams, including the Nationals, hadn't hired certified trainers at their Dominican facilities.

"For us, the health of the kids is an essential and critical part. We've put emphasis on improving existing protocols from the very beginning. We're very proactive in that sense," Pérez said.

Enrique Rojas writes for ESPNDeportes.com.