Commissioners can customize their Custom Leagues in many ways—even after completing the registration process.
The Edit League Settings option found among the Commissioner Tools, allows for alteration of virtually all settings right up to draft day, and many all season long.
Head-to-Head Settings:
| Type of Scoring | Standard; One-Win; Fantasy Points |
| Number of Divisions | One; Two |
| Teams in League | 2-20 (even numbers only) |
| Players per Team | 8-30 |
| Player Universe | All baseball; AL only; NL only |
| Maximum Player Acquisitions per Season | None Allowed; No Maximum; 1-100 |
| Maximum Player Acquisitions per Week | None Allowed; No Maximum; 1-25 |
| Maximum Trades | None Allowed; No Maximum; 1-40 |
| Trade Deadline | None; August 2, 2009; August 9, 2009; August 16, 2009; August 23, 2009; August 30, 2009 |
| Trade Review | League Votes; Commissioner; Yahoo! Sports |
| Trade Reject Time | No Protests; 1-7 days |
| Waiver Period | No Waivers; 1-7 days |
| Can't Cut List | None; Yahoo! Sports |
| Post Draft Player Status | Follow Waiver Rules; Free Agents |
| League Start Week | Week 1 - Week 22 |
| Roster Changes | Daily-Tomorrow; Daily-Today; Weekly |
| Minimum Innings Pitched per Team (each week) | No Minimum; 1-50 |
| Trade Offers Expire in | 10 days |
Rotisserie and Fantasy Points Settings:
| Type of Scoring | Rotisserie; Fantasy Points |
| Teams in League | 1-20 |
| Players per Team | 8-30 |
| Player Universe | All baseball; AL only; NL only |
| Maximum Player Acquisitions per Season | None Allowed; No Maximum; 1-100 |
| Maximum Trades | None Allowed; No Maximum; 1-40 |
| Trade Deadline | None; August 2, 2009; August 9, 2009; August 16, 2009; August 23, 2009; August 30, 2009 |
| Trade Review | League Votes; Commissioner; Yahoo! Sports |
| Trade Reject Time | No Protests; 1-7 days |
| Waiver Period | No Waivers; 1-7 days |
| Can't Cut List | None; Yahoo! Sports |
| Post Draft Player Status | Follow Waiver Rules; Free Agents |
| League Start Date | Any day from Monday, March 30 - Sunday, April 12 |
| Roster Changes | Daily-Tomorrow; Daily-Today; Weekly (choose any weekday) |
| Maximum Games per Position (Non-Pitchers) | No Maximum; 50-180 |
| Maximum Innings Pitched per Team | No Maximum; 25-2000 (Increments of 25) |
| Trade Offers Expire in | 10 days |
All League Roster Positions (Min-Max):
| First Base | 0-5 |
| Second Base | 0-5 |
| Third Base | 0-5 |
| Shortstop | 0-5 |
| Catcher | 0-5 |
| Middle Infield | 0-5 |
| Corner Infield | 0-5 |
| Any Infield | 0-5 |
| Left Field | 0-5 |
| Center Field | 0-5 |
| Right Field | 0-5 |
| Any Outfield | 0-10 |
| Utility (Any Player) | 0-10 |
| Starting Pitcher | 0-10 |
| Relief Pitcher | 0-10 |
| Any Pitcher | 0-10 |
| Bench | 0-20 |
Statistical Categories:
| Batting | GP -- Games Played; GS -- Games Started; AVG -- Batting Average (Rotisserie, Head-to-Head Only); SLG -- Slugging Percentage (Rotisserie, Head-to-Head Only); OBP -- On-Base Percentage (Rotisserie, Head-to-Head Only); OPS -- On-base + Slugging Percentage (Rotisserie, Head-to-Head Only); FPCT -- Fielding Percentage (Rotisserie, Head-to-Head Only); AB -- At Bats; R -- Runs Scored; H -- Hits; 1B -- Singles; 2B -- Doubles; 3B -- Triples; HR -- Home Runs; RBI -- Runs Batted In; SH -- Sacrifice Hits; SF -- Sacrifice Flys; SB -- Stolen Bases; CS -- Caught Stealing; BB -- Walks; IBB -- Intentional Walks; K -- Strikeouts; GIDP -- Ground Into Double Play; TB -- Total Bases; PO -- Putouts; A -- Assists; E -- Errors; XBH -- Extra Base Hits; NSB -- Net Stolen Bases; SB% -- Stolen Base Percentage (Rotisserie, Head-to-Head Only); CYC -- Hitting for the Cycle; PA -- Plate Appearances; SLAM -- Grand Slam Home Runs; OFA -- Outfield Assists; DPT -- Double Plays Turned; CI -- Catcher Interference |
| Pitching | APP -- Pitching Appearances; GS -- Games Started; ERA -- Earned Run Average (Rotisserie, Head-to-Head Only); WHIP -- WHIP Ratio (Rotisserie, Head-to-Head Only); K/9 -- Strikeouts per Nine Innings (Rotisserie, Head-to-Head Only); K/BB -- Strikeout to Walk Ratio (Rotisserie, Head-to-Head Only); W -- Wins; L -- Losses; CG -- Complete Games; SHO -- Shutouts; SV -- Saves; OUT -- Outs; H -- Hits; TBF -- Total Batters Faced; R -- Runs; ER -- Earned Runs; HR -- Home Runs; BB -- Walks; IBB -- Intentional Walks; HBP -- Hit Batters; K -- Strikeouts; WP -- Wild Pitches; BLK -- Balks; SB -- Stolen Bases Allowed; GIDP -- Batters Grounded Into Double Plays; SVOP -- Save Chances; HLD -- Holds; TB -- Total Bases Allowed; IP -- Innings Pitched; PC -- Pitch Count; 1BA -- Singles Allowed; 2BA -- Doubles Allowed; 3BA -- Triples Allowed; RW -- Relief Wins; RL -- Relief Losses; PICK -- Pickoffs; RAPP -- Relief Appearances; OBPA -- On-base Percentage Against (Rotisserie, Head-to-Head Only); WIN% -- Winning Percentage (Rotisserie, Head-to-Head Only); H/9 -- Hits Per Nine Innings (Rotisserie, Head-to-Head Only); BB/9 -- Walks Per Nine Innings (Rotisserie, Head-to-Head Only); NH -- No Hitters; PG -- Perfect Games; SV% -- Save Percentage (Rotisserie, Head-to-Head Only); IRA -- Inherited Runners Allowed; QS -- Quality Starts; BSV -- Blown Saves; NSV -- Net Saves |