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Rules & Regulations

The IISL generally follows the Amateur Softball Association (ASA) Official Rules of Softball and the Chicago Social League as the basis for rules and regulations for play except if otherwise voted on by the IISL Council and cited in the League Rules.

  1. A “strike mat” will be used to determine balls and strikes. If the softball touches any part of the mat on a legal pitch (8’-14’ arc), it will be considered a strike. Pitches touching any part of the plate WILL BE considered a strike as well .The strike mat is only used for calling balls and strikes. The strike mat is not home plate. Therefore, when a runner is trying to score, he/she must touch home plate in order to score. If he/she touches the strike mat and not home plate, and then is tagged, the runner will be tagged.
  2. All batters will start with a one ball, one strike count. A foul ball with two strikes will result in the batter called out.
  3. All games are seven innings or 60/75 minutes (warm up time included); the last inning will start 10 – 15 minutes to the hour. The captains will enforce this rule and will make the call at the top of the final inning. If a game is tied at the end of seven innings, extra innings will be played only if there is time. If there is not time (at least 10 minutes left in the hour), the game will end in a tie. Note: Due to differing circumstances in each and every game, some games will finish short of 60/75 minutes in length, while others might run over. Please respect everyone’s time and make appropriate adjustments.
  4. A maximum of 10 players in the field at all time. A team can start a game with a minimum of 8 players. If a team has less than the minimum required number of players it is up to the opponent and/or umpire as to what is allowable.
  5. **coed**For co-ed games:
    1. Female fielders requirement: Instead of 3 female fielders, we will now require two female fielders. For example:
      1. 8-2
      2. 7-1
      3. 6-0
  6. Teams may bat more than ten players. Designated hitters will be allowed for female players.
  7. All Teams may bat more than ten players; however, COED teams must bat at least 3 women in the batting lineup. In situations where additional players wish to bat, the line up must adjust as close to a 3:1 ratio as possible.  ***Male or Female players CANNOT bat twice in the lineup – in the past we allowed this, this year we will enforce this rule.
    •  If you cannot meet this requirement, an automatic out will be issued for each female you are missing. For Example the batting lineup:
      1. 7-9men: 3women
      2. 4-6men: 2 women
      3. 6men: 0 women  (3 automatic outs for missing women)
  8. There are no male/female batting order rules other than the 3 to 1 ratios and the scenario discussed above. (i.e. You may bat 6 men followed by 3 women or vice-versa)
  9. Games start on time!!! Teams must be prepared to play.
  10. Between innings, the pitcher is only allowed one warm-up pitch unless it is a new pitcher entering the position. There is no infield or outfield warm-up between innings.
  11. A mandatory 2 and 2 count will now be enforced at the top of the 5th inning for every game without exception. A waiver may be obtained if there are no games behind you and at the consent of BOTH managers. Managers are advised to be considerate for everyone’s time BEFORE giving consent
  12. Forfeit rule: 10 minutes after game time. If one team has less than the minimum number of players (For co-ed: 8 total-2 females) at ten past the designated start time, the team that is short players will forfeit. If however, the opposing team wishes to allow the team to play with less than the minimum amount of required players, the game may be played as an official game. This must be agreed to by both team captains.
  13. Game mercy rule: (The home team will always get their last at bats)
    • 15 runs after four complete innings
    • 10 runs up after five complete innings
  14. Inning run limit rule: There will be a 7 run limit per inning during innings 1-6. (Exception : unlimited runs may be scored if one of the innings 1-4 is declared the final inning of the game.) Unlimited runs may be scored in inning 7, or in any extra innings.
  15. No leadoffs or stealing allowed. Runners may leave the base once the ball is hit by the batter. If a runner leaves early, the ball is dead and the runner is declared out. If this is the 3rd out of the inning the batter will be first up in the next inning.
  16. All Bats must conform to ASA guidelines. IISL will use Yellow/Gold dot ASA approved balls.  For the regular season, the ball All inquries must be resolved by the team captains.
  17. Base runner to defensive player contact will be closely managed by team captains. Any excessive contact or collision will result in an “out” and/or ejection. This includes contact with the catcher. The runner will be rewarded home plate if the catcher blocks the basepath of the runner.
  19. All thrown balls are deemed out of play when:
    • Ball is thrown over the fence
    • Ball is thrown beyond the fence
    • Ball is thrown beyond the imaginary line extending from the end of the backstop (if there is no fence).
    • This imaginary line applies to overthrows and caught fly foul balls.
    • If Ball is overthrown and hits the fence behind the 1st or 3rd base lines but does not travel out of play, this is NOT considered out of play and the runner may advance, BUT at his/her own risk.
    • On overthrows out of play, the runner is granted the base he/she is going to (at the point of the throw) plus one more base. Note: in cases where a base runner runs past first base, he/she must make a clearly aggressive turn towards second base to be granted 2nd and 3rd in overthrow situations.
  20. On an infield fly (any fly ball within the infield with significant arc and deemed an “easy catch”) with less than 2 outs and runners on 1st and 2nd or 1st, 2nd and 3rd, the batter is automatically out and runners can advance, BUT at their own risk.  If there is no umpire, it is the responsibility of the batting team’s captain to announce the infield fly rule during the play.
  21. All outfielders must remain behind the chalked and/or coned “outfield line” (150 feet) when a female is up to bat. (only applies to Coed ) In most cases the cone should be placed 2 ½ times the distance of the basepaths (65 feet). There cannot be more than 6 players on the infield at any one time.  Once contact has been made the outfielders may cross the line. If an outfielder crosses the line before contact has been made the female may be awarded first base.
  22. In certain facilities a home run rule may apply. A maximum of 5 home runs per team will be credited. All balls hit over the fence after the limit will result in a single with runners advancing only one base
  23. 2-2 count in the fifth inning: Reminder, regular season this is optional.  During Tourney this will be enforced.
  24. Pitching arc: Reminder, pitching arc is 6′ to 14′. During Tourney, the umpires will enforce this.
  25. Base running: Reminder, catcher must stand “IN FRONT” of the plate when receiving a ball to make a play, runners should avoid sliding if a collision is the most likely end result and, finally, runners should not run over fielders even if they are in the middle of the base path.
  26. Tourney Roster:  All players can only commit to one roster. No exceptions.
  27. Helmets and Pitching masks – Are not required but strongly encouraged.
  28. Strike Mats are typically 17″ x 21″. This year we are extending the strike zone to at least 21×21″. You can buy these here: (select 21×35)
  29. This year for softballs, women will use an 11inch ball and men will use a 12in ball. This is the recommendation from ASA.
    1. Softball men: 12-inch balls with a COR of 52 and compression of 300 lbs.
    2. Softball women: 11-inch balls with a COR of 52 and compression of 300 lbs -or- 11-inch balls with a COR of 47 and compression of 375 lbs
  30. Bats: ASA Guidelines:
  31. All teams will make playoffs but format will be determined soon. Regardless of the outcome, your regular season record will determine seeding. More information to come.
  32. Game balls will be furnished by the home team (11 and 12in) during the regular season. Approved softballs must be factory stamped with TAAF, ASA, USSSA, or NSA licensed trademark for slow pitch league play.
  33. Automatic walk rule applies to league play. If the male (batting before the female) walks, (intentional or unintentional), it is an automatic two-base walk. The female has the option to hit or walk.
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