When does a player become eligible for the Rule 5 Draft?

Question

During the annual meetings of baseball every winter there is a short reorganization of baseball teams. It's called the Rule 5 draft.

During this draft a certain group of players from each team are protected and a certain group of players can be selected by the rest of the teams.

I know that specifically players that have been recently drafted, and players on the 40 man roster are not eligible to be taken in the Rule 5 draft.

What I'm unclear on is when a player becomes eligible for the draft, and how he might be protected in addition to lack of service time and being added to the 40 man roster.

What are the eligibility criteria to be selected in the rule 5 drift and what ways are there to protect a player outside of the 40 man roster?

Answer 1

The key passages from the MLB's Rule 5 Draft description are.

"Players who were signed when they were 19 or older and have played in professional baseball for four years are eligible, as are players who were signed at 18 and have played for five years."

"All players on a Major League Baseball team's 40-man roster, regardless of other eligibility factors, are "protected" and ineligible for the Rule 5 Draft."

The idea is to prevent teams from "warehousing" players that have at least 4-5 years of minor league experience (depending on the age they were signed). By that time, a player should be "on his way" to the majors.

Membership on the 40-man roster suggests that the player has a future in the major leagues, even if he is still "technically" in the minors, because he may be called up any time a spot becomes available. By the end of the sixth year in the minors, a player will either have been promoted to the major leagues, or else have been released by the team. In that case, other teams may choose to sign him.

The Rule 5 Draft gives other teams a "head start" on signing minor league players after the ends of their fourth and fifth years that would otherwise be eligible to be signed at the end of year six.

Answer 2

The MLB's description of Rule 5 Draft is available here, wax.

In general, the information specifically about the Rule 5 draft is extremely vague/generic, unfortunately.