The Co-Commissioners will make rule interpretations. These interpretations may be appealed to the ASFBL Arbitrator, who may over-rule any interpretation. The Arbitrator’s decisions are binding (but not retroactive) in subsequent weeks.  (Note: We’ve only ever had 1 decision to to the arbitrator in 25 years.)

Collusive trading is not allowed. If an owner believes that a trade is collusive, that owner must submit a written protest explaining the reasons to both Co-Commissioners. The Co-Commissioners will forward the protest to the League Arbitrator, who will issue a ruling before the next week. In the event that the Arbitrator cannot make a ruling within a week, the ASFBL Co-Commissioners will make a temporary ruling that will be binding until the Arbitrator can be reached.

If an owner calls in a lineup that does not conform to the rules listed below, the computer simulation will alter the lineup so that games for the week can be played. This may result in the waiving of players; and those waivers will be binding.

Rights to Players

All owners have the rights to all players on their team’s Major League roster, starting Opening Day. In the event of a Major League trade occurring on Opening Day, however — in which the rights to the player could be argued on either side — presumption of ownership will then defer to the team that the player in question first bats or pitches for.

The listing will be used as the source for official Opening Day lineups. All owners also have the rights to any player initially used on their team’s AAA affiliate before and as of MLB’s Opening Day.

Owners do not have rights to players who are not on either their team’s AAA or Major League roster.

Players are the property of the team they first play for in a given seaston at either the AAA or Major League level.

No post-Opening Day real life transactions affect the rights to ASFBL players.

Players who accrue statistics but quit or are ineligible in real life will continue to be eligible in ASFBL, although that eligibility may be appealed to the League Arbitrator.  Dead players cannot be used.


All owners have two ASFBL rosters: the “Active Roster” includes all the players that are eligible for use in a given week and the “Inactive Roster” includes all other players that the Owner has the rights to.  Active roster size will follow actual MLB rules, which is 26 players all year during the 2023 season.

(Removed: in the 2022 season it will start with 28 players, contract to 26 on May 1, and is limited to 13 pitchers after May 1.)

If an owner moves a non-injured player from the Active to the Inactive Roster, that player is thereby waived, and is thus eligible to be claimed by any other owner. (Waived players are awarded to the claimee with the lowest ASFBL record at the time of the claim.  Teams cannot claim their own waived players.)

If an owner moves an injured player from the Active to the Inactive Roster, that owner receives one “Free Waiver.” A free waiver can be used to the subsequent week to protect one player who would otherwise be waived. This free waiver does not have to be used to protect the player who the ASFBL owner calls up to replace the injured player. If a lineup is entered, and it is not specified by the owner that a free waiver is being used, it will be assumed that a free waiver is not being used. However, if — due to a problem with a lineup — the Co-Commissioners are faced with a choice of waiving a player or using a free waiver, they will use the free waiver if one is available.

If more than one Owner claims a given player on waivers, that player will go to the Owner with the lower ASFBL winning percentage.

A player successfully claimed in a given week off waivers must go immediately to that owner’s Active Roster the very next week. If the owner does not insert the claimed player into their lineup, the computer simulation or Co-Commissioners will have to insert that player, and adjust the lineup accordingly. This means that one of the owner’s other players would be waived. Pitchers acquired from the Waiver Wire must pitch upon active roster insertion. The “Never Pitch” option can be used in subsequent weeks.

Trading Deadlines & Trades

If a player you traded is not on the real life roster as of Opening Day, the entire trade involving that player is canceled.

Limitations on trading include:

  • No more than 2 separate trades per team before Major League Baseball’s Spring Training begins.
  • No more than 6 separate trades per team before MLB’s Opening Day begins.
  • No more than 5 players, per team, in any deal (including “Players to be Named”).
  • No more than 1 “Player To Be Named” (per team) in any deal.
  • No more than 2 deals with the same team in any given week.
  • No more than 6 deals with the same team in any given season.

The ASFBL trading deadline will follow Major League Baseball’s trading deadline (usually the following week) each season.  As of 2022 this is set by the MLB Commissioner each year.

Following MLB practice, there are no waiver trades after the trade deadline as of 2022.  (Previous rule, for history’s sake: After the ASFBL trading deadline has passed, any players involved in potential trades must first clear the waiver process (i.e., be listed on the Waiver Wire and not claimed by an owner with a lower ASFBL winning percentage than the intended trading owner.  If a player is claimed off waivers after the trading deadline by an owner other than the intended trading owner, that player can be withdrawn from waivers by the owner attempting to trade. Note that players waived from the Active Roster during this process are not eligible for waiver withdrawal. If an owner other than the intended trading owner claims a player, and that player is not withdrawn from waiver by the trading owner, the claiming owner must then insert that claimed player into his or her active roster for the next lineup. (This is the same rule applying to players claimed off the regular ASFBL Waiver Wire.)

Free waivers can be traded. (Inactive: A free waiver may not be used to clear a traded player from the waiver process after the ASFBL trading deadline.)

All trades must be verified by both owners involved on the Trades Page (preferably right away, but) no later than the deadline for lineup submissions that given week.

If a trade is agreed to by both owners, and only one owner verifies it, the trade will not be recorded for that week’s lineups.

Stat Use, Injuries & Suspensions

All transactions are done on a weekly basis.

The injury list appearing on-line in the CBS baseball MLB injury report website as of the download date will be used to determine eligibility.  Cases of inaccuracy can be appealed to the Co-Commissioners and instances of inaccuracy can be corrected; if after research with other information sources the injury status remains ambiguous the CBS baseball site status will be the default.

A player who is listed on that injury list (other than “day to day”) will be ineligible for that entire week’s worth of games.

Players serving 50-game suspensions will be treated like disabled players. Players serving shorter suspensions will receive no special status. Basically, if a guy hits a 50-game suspension, you can’t use ’em, and if they have a shorter suspension, you can. In the past, we have approached affected owners on a case-by-case basis and asked them to voluntarily stop using players, and thus far everyone has. However, given that it could be a large number of players on and after 2014, a league standard seemed in order.

A player who has at least one at bat or pitches 1/3 of an inning any time before the publication of that injury list will be eligible for that entire week’s worth of games.

A player is considered ineligible only if disabled, suspended per the rules above, is rehabilitating an injury and physically not ready to appear in an MLB game, or through special appeal to the Co-Commissioners.

Real Life versus ASFBL Games

Major League rainouts or postponed games will not be counted in the ASFBL schedule of games.

Player Eligibility to Start & Play

All owners must have a starter at every infield position, a starting catcher, three outfielders, and a designated hitter.

The outfielders can play any outfield position (e.g., an owner could start two right fielders).

Each player has an ASFBL Defensive Rating for the two positions played most frequently. For example, if a player has played infield, first base, and some outfield, he will only be allowed to play in ASFBL at the two positions played most frequently in real life.  As of 2023, data is pulled from the BaseballSavant website, and it essentially uses “balls touched” to determine frequency (as opposed to “innings played”).  Stats are downloaded separately for catchers, infielders, and outfielders.  Essentially, “outs above average” are used for infielders and outfielders and catcher blocker ratings are used and normalized on a 940-999 scale, with 970 being average.

Long note on fielding eligibility: Baseball-Savant does not track innings or games at a position.  The catchers page has “block opportunities.”  The outfield page also has “opportunities” to catch a ball.  The infield page has “opportunities” but it isn’t visible; if you right-click the page and collect “view page source” you can find a field called “n” that is the number of infield opportunities.  The computer tallies all these “opportunities” and makes a player eligilbe and the 2 positions where they have seen the most opportunities and updated that in the week stat download.  I know that isn’t very straightforward, and if someone can find a place to get a more straightforward rating please send it my way.

The conversion chart below tells you how many points a player loses from his current fielding rating if he is moved to a position that is not his 2 most frequently-played positions. Thus, a shortstop with a fielding rating of 980 moved to second would lose 10 points and have a rating of 970. An outfielder with a rating of 960 moved to catcher would lose 50 points and have a 910 rating. If a player has played two positions, the player at the new position will get the higher adjusted rating at the new position.

Conversion Chart
New Position
Old Position C 1B 2B 3B SS OF
DH only 910 925 925 925 925 940
C -15 -50 -15 -50 -50
1B -50 -30 -10 -40 -40
2B -50 -20 -10 -15 -30
3B -50 -10 -25 -25 -30
SS -50 -20 -10 -5 -25
OF -50 -30 -45 -40 -50

Keep in mind that your catcher will get a ton of chances, making it a crucial defensive position.  In addition to the adjustments on the conversion chart, a player playing out of position at catcher will have an opponent stolen base success rate of 95% and more base runners will attempt to steal.

Also keep in mind that the shortstop will get more chances than other infield positions, making it slightly more crucial than other infield spots.

If you play a player out of position in a given week, you must re-verify each subsequent week that you play the player in that position. A designated hitter who has played two or more positions in real life counts as a player out of position for lineup purposes, although obviously the player won’t field any balls.

Batters who pitch a few innings in emergency situations will not be eligible to pitch.  Otherwise we use the “Shohei Ohtani” rule.

A player must have either at least three MLB at-bats or one MLB inning pitched to be eligible for your ASFBL active roster. Remember, a sliding scale on performance is imposed on those ASFBL players who exceed 135% of their real life batting or pitching totals, and it is not necessarily to an owner’s advantage to use players who have high BAs or low ERAs with minimal game time.

Roster Spots

Each owner’s ASFBL active roster will be set at twenty-six players. This means nine starting position players including a DH.  A starting pitchers must be designated for all games in the week.  The MLB limit on 13 pitchers is in effect, although a pitcher designated “Never Pitch” for a given week’s worth of games and not listed as a starter will not count against the number of total or minor league pitchers.

Any pitcher claimed on waivers cannot be designated “Never Pitch” the first week he is used in your active roster.

Owners should also consider rotating relievers to the #5 starter spot in the weeks when that spot is not slated to pitch. Thus, by sending an over-worked reliever to the #5 spot when the #5 spot gets skipped, owners are essentially giving him a week off.

Open Teams

If the Co-Commissioners are unable to fill all the teams in ASFBL, they are authorized to offer teams at lower rates to fill the league. Owners who play for lower rates will be eligible for prizes at the proportionately lower rate as well (i.e., $75=75% of a designated prize).

If the Co-Commissioners cannot find owners for teams, the computer simulation will manage those vacant teams. The computer can make trades, but owners must allow a week for the submission and reply of a trade offer to the computer.

No Roster Expansion

Roster will not (cannot) be expanded near the end of the regular season like they are in Major league Baseball.  This rule may be moot following the 2021 season.

Minor (AAA) Leaguers

Each owner may have three minor league players on their active roster at one time. Only one of those three players may be a pitcher. However, two AAA pitchers can be carried on the active roster when one of those AAA pitchers is designated as “Never Pitch.” Teams can thus use four AAA players, two of which can be pitchers. However, only one of those two AAA pitchers can pitch in a given week.

The performance of minor leaguers will be adjusted to approximately reflect Major League performances, approximately a 17% reduction with additional adjustments for low AB or IP.

Minor leaguers will not be eligible for season play until two weeks worth of AAA stats become available to ASFBL.

Minor Leaguers do not have a set number of “options” in ASFBL. They may be promoted and demoted an unlimited number of times, provided they are protected with a free waiver or clear waivers each time they are moved off the active roster.

Minor leaguers are generally not available until the MiLB schedule has had 3 weeks of play and thus may not be available for early-season rosters.  The date of availability will be announced in newsletter.

As of 2018:  As soon as a AAA player is called up in real life and accumulates 10 Major League innings pitched or 25 at-bats, those Major League stats replace minor league stats. Upon promotion of any sort any accrued ASFBL fantasy stats to that point will be reset (and the accrued minor league stats would be irrelevant to subsequent performances).

Until 10IP/25AB, a sliding scale will average AAA and MLB stats. For batters, the actual AB is divided by 25 to create an adjustment percentage, and the final stats are a weighted average based on the adjustment percentage for MLB stats. For example, if a guy has 13 real AB, the adjustment percentage is 13/25 = 52%. His stats will be 52% MLB and 48% AAA, so if he’s hitting .200 in MLB and .293 in AAA the average is (.200 * .52) + (.293 * .48) = .244. For pitchers, the calculations are the same but with IP replacing AB and 10 as the divisor rather than 25.

2006 Addendum: Minor League pitchers must accrue a minimum 10.0 innings pitched and batters must accrue 10 at bats before they are eligible to be used in ASFBL.


Real-life playoff stats will not be included and stats will be frozen at their end-of-year totals.

ASFBL statistics will continue to accumulate through the playoffs.  There will be a 2-day break between the last game of the regular season and the start of the playoffs.

Teams advancing to the playoffs follow MLB rules (seeds 1-3 are division winners, seeds 4-6 are the next best records, no re-seeding after the bracket is set).  The wildcard round will be 5 games and follow a 2-2-1 format with off days in between.  All other rounds are 7 games following a 2-2-1-1-1 format with off days in between.

Regular season statistics will NOT be cleared and will continue to accumulate, with the exception of the over-use factors, which will be frozen at their final regular season figures.  For example, a pitcher over-used at 145% on the last day of the regular season will have an over-use factor of 145% for all of the playoff games, but all other statistics will continue to accumulate.

A three man rotation may be used in the playoffs. There will be a fatigue adjustment for playing on three days’ rest.

For the World Series (and Interleague Play), the real life home and away designated hitter rule will apply. Owners whose teams are in the World Series will call in two lineups: one with and one without a designated hitter.  [2022 update: This is moot so long as both leagues have the DH.]

Postseason & Wins Above Reality Prizes

A “games ahead” measure over the real life counterpart will be used in the Wins Above Reality award categories. Prizes will be awarded up to the top ten finishers whose ASFBL regular season records are higher than their real life counterparts.

Very often, however, teams participating in the ASFBL postseason are also ranked in the Wins Above Reality categories. In these instances, that owner will choose between the higher of their two awards. For example, the Red Sox were in the Postseason last year but were knocked out in the First Round. The Red Sox owner has also qualified for Second Place in Wins Above Reality, and opted for that higher monetary prize.

Postseason prizes are awarded for playoff teams and top Wins Above Reality finishers.  Leo sets the payout totals each year.  Our general rule of thumb is to make sure the NLCS or ALCS runner-up receives a slightly higher award than first place in wins above reality, and that the NLDS or ALDS runner-up receives a slightly higher award than second place in wins above reality.