MLB's rules are complex and convoluted, but they're not hard. I've heard various people in front offices referred to as "rules experts" or - my favorite "waivers experts." The rule on waivers (Rule 9) runs nine pages, a large part of which revolve around resolving the order of claims. We're not talking Finnegan's Wake here; anyone with the rules and perhaps a pen and paper can figure these out pretty quickly. The problem is that the rules aren't very public, and as a result, members of the media and the average fan are all at a disadvantage when it comes to some of the more esoteric rules or to baseball's inconsistent nomenclature.

Here are a few rules that seem to cause a lot of confusion with my best efforts at explaining them.

Waivers

I'll never forget something I saw this spring on a message board I won't name, when Chris Snow of the Boston Globe (and now director of hockey operations for the Minnesota Wild) reported that Hee Seop Choi couldn't be sent to the minors without clearing waivers. Because most fans weren't familiar with the rule in question, the immediate assumption was that Snow was wrong. And one poster in particular ripped Snow, saying it was just "sloppy reporting" and then saying how every beat writer should learn the transaction rules.

Except, of course, Snow was right. How odd that the professional should know what he was talking about.

There is a rule rarely invoked in baseball that creates a situation where a player who has options remaining still has to clear waivers to be sent on an optional assignment. If the assignment is to begin at least three full calendar years from the date of the player's first appearance on a 25-man roster, then the player can not be sent on an optional assignment without first clearing major league waivers. These waivers are revocable, and players usually clear those waivers without incident.

There are three kinds of waivers in MLB:

• Unconditional release waivers. These are self-explanatory. A player on release waivers can be claimed for $1, and the claiming team assumes the player's contract. The player does have the right to refuse this claim and become a free agent.
• Outright or special waivers. The name changes depending on the time of year, but the effect is the same. These are the waivers you use to kick a player off of your 40-man roster. They're also the waivers to use when you wish to send a player who is out of options to the minors (thereby also removing him from your 40-man). These waivers are irrevocable, meaning that if you place a player on outright waivers and he is claimed, you can not pull the player back off waivers.
• Major league waivers. These are the waivers in question during August. Between 4 pm on July 31st and the end of the season, players must clear major league waivers to be assigned to another major league club. These waivers are revocable, and they are also the waivers required for players in Choi's situation, who have options remaining but are more than three calendar years removed from their debuts on major league rosters. Although these waivers are revocable, if a player on major league waivers is claimed and the waiver request is revoked, a subsequent major league waiver request in the same waiver period will be irrevocable.

So, as of the day that this article first appeared, any player who first appeared on a 25-man roster prior to August 3rd, 2003, must now clear major league waivers to be optioned to the minors.

Service time

Some bullet points on service time...

• One year of major league service is defined as 172 days of service, but a major league season actually runs around 183 days. A player can only accrue 172 days of service during a season, but he doesn't have to be on a roster from wire to wire to get that many days. This means that a team that wishes to hold a player in the minors long enough to push his free agency date back by one season must wait at least eleven days (and probably about two weeks, just to be safe) before recalling him.
• Days spent on optional assignments shorter than ten days don't count against your service time. If you're sent down on Friday and are recalled on Monday, you get Saturday and Sunday's days of service as well.
• The cutoff for "super-two" status (referring to players with between two and three years of service who are eligible for salary arbitration) is not fixed; all players with at least 2 years and 0 days of service but no more than 2 years and 171 days (2.171) of service are ranked in descending order by total service time, and the top 16% are granted super-two status. The cutoff is usually somewhere between 2.130 and 2.135; to the best of my knowledge, it's never been below 2.120, so a player recalled after June 5th or so is in the clear.

When an option isn't an option

If a player is sent out on one or more optional assignments during the course of a season, but the total number of days spent on those assignments is fewer than twenty, then he's not charged with an option. So there.

The fourth option

Everyone knows that a player who is added to a 40-man roster for the first time may be sent out on optional assignment in up to three years, which are commonly referred to as "option years" or just "options." But once in a while, a player ends up receiving a fourth option year. Here's the text from the MLB rulebook:

"Contracts of Major League players who, prior to commencement of the current season, have been credited with less than five seasons in professional baseball ... shall be eligible for a fourth optional assignment, without waivers, during that season. For purposes of this Rule 11(c), 90 days or more on the Active List during a championship season shall constitute a 'season of service.' ... [if] a player is placed on the disabled list after the player has been credited with 60 or more days of service in any particular season, the Disabled List time shall be counted to the player's credit."

So what are we saying here?

• A player who is currently entering his fourth or fifth pro season and already has been optioned in three separate years gets a fourth option. Delmon Young has been optioned in three years (2004, 2005, 2006) and he'll get a fourth option in 2007, which he's doing his best to earn.
• A player who has missed one or more seasons to injury - meaning an entire season, or enough time to accrue fewer than 90 days on an active roster - may get a fourth option if, exclusive of those injury-shortened years, he has fewer than five full seasons in pro ball. A season in which he's on an active roster for 60 days or more and then gets hurt still counts as a full season, but a season in which he's hurt and then comes back and gets 60-89 days of service after the injury does not.
• Seasons spent entirely in short-season leagues (the New-York Penn, Northwest, Pioneer, Appalachian, Gulf Coast, and Arizona Rookie Leagues, as well as the Dominican and Venezuelan Summer Leagues) don't count as seasons for the purposes of a fourth option.

As you might imagine, more players are eligible for fourth options than you might have realized, but they often don't come to light because the players are low-profile or because they're kicked off of 40-man rosters before the fourth option comes into play.

Prior outrights

The first time a player is placed on outright/special waivers, he must accept the outright assignment if he clears. All subsequent times, however, he has the right to reject the outright assignment and become a free agent, or he may accept the outright assignment but become a free agent at the end of the season (unless he's back on a 40-man roster at that time).

In addition, a player with at least three years of major league service may also reject an outright assignment at that moment or at the end of the season, regardless of whether he has a prior outright. Players receive these rights under Article XX of the Basic Agreement, and are sometimes referred to as Article XX free agents within the industry, although they're more often lumped in with minor league free agents in the press because the time of their free agency is similar.

As you can see, MLB's roster rules aren't difficult, just complex. I think MLB could do a better job of explaining the rules to fans, since there's a huge appetite for information on rosters, waivers, and service time, but I hope this has at least cleared up a few of the more common quirks in the system.

Keith Law is the senior baseball analyst for Scouts Inc. Before joining ESPN, Law served as special assistant to the general manager of the Toronto Blue Jays and was a writer for Baseball Prospectus. His writes for ESPN.com and for ESPNdeportes.com, and he has appeared on ESPNews' The Hot List and the Pulse, ESPN's Outside the Lines, and on ESPNRadio.