OSSO Sports and Social

Tulsa Mushball Softball Rules


  • 7 innings or 50 minutes.
  • Completing a set number of innings/ time limit ends a game.
  • Mercy rule is in effect if there is an Ten (10 or more) run difference at the end of the 5th inning, or any inning after at the request of the losing team.

Team Lineups

  • 3 players of the same sex cannot bat consecutively until all other players of the sex in the minority have batted. (ex: M,M,F,M,M,F… until all Females have batted)


  • Mushball Softball is played with a 16″ Softened Softball
  • Pitch must be pitched underhand with no spins and at an average pitch speed with a pitcher’s full intent to pitch a “strike”.
  • Ball must be pitched with a floor of 6 ft & a ceiling of 12 ft
  • A strike is any pitch that hits the plate, hits within a foot on either left or right side of the plate or a foot behind the plate that has met the floor/ceiling requirements.
  • No Walks
  • *Pitcher’s full intent is to throw a repeatable, hittable pitch


No Fielding Gloves are used in the field

Team’s Fielding Lineup can contain a maximum of ten Players (4m/4f MINIMUM)

  • Non-Catcher Fielders (including the pitcher) must stay behind the imaginary line between 1st & 3rd until the ball makes contact with a bat
  • Normal Fair/Foul Lines Apply
    • Bats will be provided by OSSO.
      *Batters MAY NOT use their own bat.


  • Batters get 4 Non-Balls to put the Ball in Play.
  • “Non-Ball” = Called strikes, “Swinging” strikes, & Fouls
  • Strikes and Fouls are counted as the Same.
  • “Bunting” is not allowed
  • If a player is too injured to bat, they are an automatic out


  • Bases are 60 feet Apart
  • No Stealing of Bases
  • No Leadoffs
  • A runner CAN advance at their own risk on a caught foul ball
  • If a player is too injured to run, the last out of the same sex will be a pinch runner. (once they have made it safely to a base)
  • If a team has less than the required amount of a particular sex to play during the regular season, the opposing captain must verbally agree to the game being counted toward the standings.
  • Pay attention to where you are as a fielder!
  • Defensive players cannot line up to start a play on a base or in the base path!
  • There should be no reason to ever have a fielder standing directly on a bag, even if a ball is in play. If you’re attempting to make a play at a base, stand to the side & have your foot tagging the base if the play is a force out.
  • IF a fielder is attempting to make a play at first base, they may touch the safest portion of either the white OR orange bag as to not trip the runner. (ex. If a throw takes the first baseman into foul territory, they may tag the orange bag for the out instead of sticking out their leg to touch the white bag) You won’t be penalized for making the SAFE play.
  • The fielding team has the right to make a defensive play on a batted ball, however interference will be called on any defensive play where a runner is impeded. (ex: a throw to first base that pulls the first baseman into the runner’s lane is interference IF the runner has to make an adjustment in order to avoid a collision) 
  • Overthrow rule – If a ball is THROWN out of play (over the fence), the head ref will signal for an overthrow. Runners get MOMENTUM.
  • If a runner is on a base or has stopped momentum towards a forward base at the time it’s called, they stay on their base.
  • Baserunners may tag the moment the ball touches a defender (runners do not need to wait for a catch to be secured before advancing bases)
  • The ball itself calls fair or foul when it’s touched (ex: a ball in foul territory touched by a fielder in fair territory is a foul ball because the ball is not in fair territory)
  • There is NO INFIELD FLY RULE (If you’re playing in the social league, and you know what the infield fly rule is, don’t be a jerk that intentionally drops an easy catch to get multiple runners out)


  • ONLY rostered players may play in playoffs. We are aware that EVERYONE thinks their team’s roster situation deserves an exception just this one time. Don’t do it. You will get caught, you’ll forfiet, you’ll be mad & it just makes what would have been a great night for everyone else really awkward. Play your match for fun & may the best team of legally rostered players win the Championship.
  • Teams must have at least 8 players on the field at all times in the playoffs, including 4 females. If a player is injured during playoffs that would cause a team to be below the 8 total required players, they may play with 7.
  • Penalty for not meeting mininum roster requirements in playoffs is a forfiet
  • If a team forfiets, Teams may play for fun, but the non-forfieting team will move on in the playoffs
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