The MLB Rule 5 Draft is one of the under-the-radar events of the MLB offseason. However, a number of extremely important acquisitions have occurred during the Rule 5 Draft throughout the history of MLB, making it one of the most important events of the winter meetings.

Every December, the MLB holds the Rule 5 Draft. If a team does not have a full 40-man roster, they are eligible to pick players in the Rule 5 Draft. Instead of drafting high school or college players, these teams draft players off of other franchises' minor league affiliates. Certain players not on a team's 40-man roster are eligible to be poached in the Rule 5 Draft. If a player who was signed at age 19 or older has not been put on their team's 40-man roster within four seasons, they are eligible to be selected. The same goes for players who were signed at age 18 or before, except they are protected from being selected until they've been around for five seasons.

A team that selects a player in the Rule 5 Draft can't just turn around and stash the player in their own farm system, though. Drafted players must stick on their new team's active MLB roster for the entirety of the next season, or they will be subject to waivers.

The Rule 5 Draft prevents teams from stashing prospects in the minor leagues. It also opens up the opportunity for players to receive a chance to prove themselves with a new organization that they were unlikely to get with their previous team. Most great prospects are protected by their team and, therefore, ineligible to be drafted. For that reason, there are rarely big-name players in the Rule 5 Draft. However, there have been plenty of players who were unheralded with their previous team, but after being selected in the Rule 5 Draft, they went on to make a tremendous impact in the major leagues. Below, we ranked the players who went on to have the best MLB careers after being selected in the Rule 5 Draft.

10. R.A. Dickey, 2007

R.A. Dickey is best known for his knuckleball pitch, but he was also a Rule 5 Draft selection in 2007 as well. Dickey was originally a first-round pick in 1996. He had a number of opportunities in the big leagues, but without great stuff, he didn't find much success. Eventually, Dickey worked on perfecting the knuckleball. That move extended his career, and he eventually won the NL Cy Young Award in 2012. Most of Dickey's production came in that season, his age-37 season. He doesn't rank higher on this list because he wasn't great for long. Still, Dickey is easily one of the most recognizable Rule 5 Draft selections ever with one of the most distinguishable pitches ever.

9. Dan Uggla, 2005

Dan Uggla had a good amount of success in the minor leagues as a part of the Arizona Diamondbacks' farm system, but the team never made him a priority for the big league roster. Eventually, they left him off of the 40-man roster and allowed him to be taken by the Florida Marlins in the Rule 5 Draft. The second baseman immediately found success, and he became the first player to be named an All-Star in the same season that they were a Rule 5 selection. This was the first of three All-Star bids for Uggla, and he was even a Silver Slugger in 2010.

8. Shane Victorino, 2002/2004

Shane Victorino, Rule 5 Draft logo

Shane Victorino was twice a Rule 5 Draft pick. The Flyin' Hawaiian was originally in the Los Angeles Dodgers farm system, and the San Diego Padres took him in the Rule 5 Draft in 2002. He was unable to stay on the Padres' active roster, so they returned him to the Dodgers. He remained in the Dodgers' system until the Philadelphia Phillies took him in the Rule 5 Draft two years later. Again, he was unable to remain on the active roster, but this time, the Dodgers declined to have him return to their team. Therefore, he stayed in the Phillies' minor league system.

Eventually, Victorino proved himself enough to warrant a stay on the MLB team. He became known for making big plays, and that earned him two All-Star appearances, four Gold Glove Awards, and two World Series victories. He became a legendary figure for both the Phillies and the Boston Red Sox, with whom he found success with later in his career.

7. Jose Bautista, 2003

Jose Bautista had a very interesting career because of the fact that he was a late bloomer. He was a late-round draft pick that didn't do much in his first few years in the league. Eventually, he was taken in the Rule 5 draft by the Baltimore Orioles. However, he only lasted 16 games in Baltimore before he hit waivers and ended up with the Tampa Bay Devil Rays. This time, he only lasted 12 games with his new organization before he was acquired by the Kansas City Royals. Bautista even had an unsuccessful stint with the Pittsburgh Pirates before he was a “waiver trade” and ended up with the Toronto Blue Jays.

A position change led to Bautista's career taking off. He became a six-time All-Star, three-time Silver Slugger winner, and two-time home runs leader. The Rule 5 Draft didn't directly lead to Bautista's success, but nonetheless, he is one of the best players to ever be taken in the Rule 5 Draft. He didn't have a normal path to stardom, and he was even one of the best waiver trade players ever, too.

6. George Bell, 1980

Originally signed by the Philadelphia Phillies in 1978, George Bell was eligible for the Rule 5 Draft in 1980. The Toronto Blue Jays took advantage, and George Bell became one of their first great players. Bell was a three-time All-Star and three-time Silver Slugger, but most notably, he was the AL MVP in 1987.

5. Josh Hamilton, 2006

A player whose talent is as known as Josh Hamilton's rarely goes unprotected into the Rule 5 Draft. Hamilton was the Tampa Bay Devil Rays' number-one overall pick in the 1999 amateur draft. The slugger was viewed as a can't-miss prospect thanks to his rare combination of power and contact ability. However, Hamilton had off-the-field issues. The outfielder struggled with drug and alcohol use, and it looked like it was going to derail his career. Failed drug tests, automobile accidents, and other incidents led to the Devil Rays not protecting Hamilton from the Rule 5 Draft. The team gave up hope on their former star prospect, but the Cincinnati Reds were willing to gamble on his talent. The Chicago Cubs picked Hamilton in the 2006 Rule 5 Draft, and they immediately traded him to the Reds.

Hamilton showed tons of promise in Cincinnati, but he once again found himself on a new team after just one year with the Reds. With the Texas Rangers, he finally found a home where he could thrive. Hamilton made the All-Star Game every season (5 times) he was with the Rangers. He became one of the best power hitters in the sport, winning the batting championship in 2010 and once even hitting four homers in a single game. He won three Silver Slugger Awards and even won the 2010 AL MVP vote. His success didn't last forever, though, as his addiction issues remained prevalent. That led to a relatively short peak, but few players' peaks were better than Hamilton's.

4. Christy Mathewson, 1900

The Rule 5 Draft has taken different forms since at least 1892. One of the first players taken in the draft, back when it was known as the “selection of players,” was Christy Mathewson. The pitcher was one of the first greats at his position. He played for the New York Giants and accomplished a lot during his 17-year career.

Mathewson won the Triple Crown twice, was a two-time World Series champion, led the NL in wins four times, and led the league in ERA and strikeouts five times. He even threw two no-hitters before becoming a Hall of Famer. Mathewson may not be a household name because he played so long ago, but he is, without a doubt, one of the best players from the MLB's early days. He is also one of the biggest success stories from what is now known as the Rule 5 Draft.

3. Hack Wilson, 1925

Hack Wilson was one of the game's first great power hitters. However, the start to his MLB career wasn't so glamorous, and a hitting slump forced Wilson to be stuck in the minors. The Chicago Cubs took advantage and selected him in the Rule 5 Draft.

Wilson led MLB in homers four times. He was a short and stocky player with unmatched strength. Wilson still holds the record for having the most RBI in a season. He had 191 in 1930. The long ball and an unmatched ability to get his teammates across home plate (he twice led the NL in RBI) led to Wilson making the Hall of Fame in 1979.

2. Johan Santana, 1999

Johan Santana, Rule 5 Draft logo

Johan Santana was somewhat unknown as a prospect out of Venezuela, and he didn't do much to change that in his first few seasons in the Houston Astros organization. The team left him unprotected going into the 1999 Rule 5 Draft. The Minnesota Twins had the first pick in the Rule 5 Draft that year, but they weren't technically the team that selected him. Instead, the Florida Marlins took the pitcher with the second pick. They immediately traded Santana to Minnesota, though, and they had to give up $50,000 to the Twins in order to cover the cost of their Rule 5 selection.

Not only did the Twins get a nice little payday because of this, but they ended up with one of the most talented pitchers ever. Santana was a four-time All-Star, two-time Cy Young winner, three-time ERA leader, and three-time AL strikeout leader. He led MLB in wins in 2006 en route to throwing for the triple crown. He even won a Gold Glove in 2007. Unfortunately, injuries prevented Santana from becoming one of the best pitchers ever, but he most definitely had one of the best primes ever.

1. Roberto Clemente, 1954

Roberto Clemente is one of the best players in MLB history overall, so he is most definitely the best player taken in the Rule 5 Draft. All MLB fans know about Clemente's legendary career with the Pittsburgh Pirates, but not many know how he ended up with the team. In 1954, the Brooklyn Dodgers gave the outfielder a hefty signing bonus for the time. Clemente's signing bonus was worth more than $4,000, and therefore he was considered a “bonus baby.” A rule at the time required teams to keep such players on their active roster, but the Dodgers wanted to develop him in the minor leagues. Clemente was still raw, and he didn't play much for the Montreal Royals. This didn't stop the Pittsburgh Pirates from noticing the raw talent he had, though, and they took him with the first pick in the 1954 Rule 5 Draft, the same year he was originally signed by Brooklyn.

The Pirates' decision proved correct. Clemente didn't need much time to develop after all, as he hit .311 by 1956. Still, it wasn't until his sixth year in Pittsburgh that Clemente made the All-Star Game. The outfielder continued to blossom for the rest of his career. He won 12 Gold Glove Awards, four batting titles, was a 15-time All-Star, won two World Series championships, and was the 1966 NL MVP. All of those accolades culminated in Clemente becoming a Hall of Famer. He is considered by many to be the greatest right fielder not named Babe Ruth, and he did it all with the team that took him in the Rule 5 Draft.