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Connie Mack 18U Rules


To promote amateur baseball as a non-profit organization. The Diamond Baseball League was formed to benefit athletes in Northeast Ohio. Teams are chosen each season based on many factors which include their high quality of play, ability to teach positive values/sportsmanship, and ability to prepare players for the next level of play.

League Directors

The Diamond League board will control all league rules and the decision-making process. Majority vote by the board is needed to overturn a rule. The franchise committee may present any rule proposals to the board which the board must approve by majority vote.

New board members must be approved by a majority vote of the coaches. If the coaches approve, the current board must approve the new member by a majority vote.

League Entrance

Teams must apply to enter the league by the August board meeting date, to which a majority of the board members must agree. The Diamond Baseball League is set up as an invitational league. All teams must reapply to enter the Diamond League for the following season.

Franchises:  The Diamond League has set parameters for long-standing quality organizations to become a Diamond League franchise. Organizations will be re-evaluated before another franchise agreement is offered.   The board holds the sole option on which organization and which team(s) in an organization are franchised.  More details are in the franchise agreement.


General Rules

The Diamond Connie Mack League follows American League rules with the following exceptions:

1) The Diamond League board will decide on how many teams to accept into the Diamond League.

1B) The league will only post team tryout information on the Diamond League website for teams that have submitted a Team Application Form. League teams can not have tryouts until the Diamond League season is "Officially" over.

2) Playing in the Diamond Baseball League excludes all teams from playing in any other league in the State of Ohio. An out of state weekend league may be allowed pending approval by the board.

3) Each team will design their own schedule. Diamond league games take priority over all Independent (non-league) games. The only exceptions to this rule are the prepaid out of town tournaments.

4) There are three mandatory coaches meetings (fall, winter and spring). Failure of attending will result in a $50 fine.

5) Standings will be kept by the Major League Baseball Games Back method.  If a game is official and ends in a tie, it will be recorded as a tie in the standings.

6) Forfeits will not be tolerated.  If a game is forfeited, the forfeiting team loses their forfeit fee.  You must send another forfeit fee of $120 in to the league before your next game or risk being removed from the league.

7a) Until the first pitch of the game, field maintenance determines whether the game will be cancelled. If there is no field maintenance, the home team will determine the playability of the field. It is the home team's responsibility to contact the opposing coach, the league office, and the umpires on all cancellations and will be responsible for umpire fees if they are not contacted. If there are any disputes, the Diamond League holds the option to determine the playability of the field and may rule a forfeit by the home team if the field is ruled playable. There must be a 24 hour notice on all non-field related cancellations.  

7b)All Diamond League games will be played with a 10 run mercy rule after 5 innings.

7c)the latest scheduled starting time is 6:00 unless it is a lighted field. A doubleheader on an unlighted field must start by 3:30 PM. 

7d)  Games will be played with a 2:30 time limit with the exception of Diamond League Tournament and Tuesdays at Tri-C.  No inning may start after 2:30 after the first pitch or if a game is called because of darkness/rain (whichever occurs sooner.)

7e) Games scheduled during the week at Cuyahoga Community College will be played with a 2:20 time limit--no inning may start after 2:20 from first pitch. Diamond League Tournament games are played with a 2:15 time limit with the exception of the semifinals and finals where there is no time limit.

7f) A game may begin after the 6 pm scheduled start time if both coaches agree.  Once the game begins, then revert back to rule 7d.

7g) Any bill the league obtains for cleanup/damage of a field will be forwarded to the team at fault.  If the bill is not settled, that team will receive penalties that may result in removal from the league.

8) Any game called due to weather, darkness, or any other reason after 3 1/2 innings if home team is winning or if the game is tied, or 4 innings if the visitors are winning is over, with the team ahead winning the game. If the game is tied, each team will receive a tie in the standings. On lighted fields, the home team must inform the umpires and the opposing team as to the availability of the lights.

-games that do not reach the 3 1/2 inning mark will be counted as a rainout.

9) If a game is halted in the middle of an inning after 4 innings of play, the game will revert back to the last whole inning played unless the home team has tied or taken the lead in the bottom half of the inning. If the home team has tied the score, the game ends in a tie. If the home team has taken the lead, the home team wins.

10a)If a tie occurs in the final regular season standings, 1) head to head only if all tied teams played each other  2) average least runs allowed vs tied teams 3)  average least runs allowed for all league games  4) average run differential vs. tied teams  5) average run differential vs. all league teams  6) coin toss

10b) If a game is cancelled because of weather, the game will not be rescheduled.

11)Team rosters will have a maximum of 24 players and a minimum of 14 players. The official Diamond League roster for each team is on the website. A player must sign a Diamond League contract and be added to the roster before he is allowed to play in a Diamond League game. Failure to meet the minimum amount of players before your first game will result in a $50 fine plus $120 additional forfeit fee due to the league. The official Diamond League roster must contain at least 50% of its players that are 17 and 18 year old. Age cutoff is May 1st.

11a) A maximum of four players per team may be rostered on a team outside of the Diamond League.

11b)All coaches must be listed on your team page on the website.  In order for a coach to file a protest, that coach must be listed on their team page on the website.  Only an opposing coach can file a protest.

12) Each parent or 18 yr old player must fill out a player contract.  If the player is 18 years of age, he may fill out the player contract. Player contracts go into effect when fully completed, signed and received by a league official in the proper amount of time.

--  It is expected that each team has at least 8 players send in a player contract by December 31st.   The Diamond League Board reserves the right to review any team that has not met this criteria as to their ability to field a team and based upon the review, the league reserves the right to remove a team.

--Player contracts must be done electronically through the Diamond League website.  If a player contract is not submitted to the league before that player participates in a Diamond League game, it will result in a forfeit.

12b) Once a parent/18 yr old player signs a Diamond League contract for a team for a given season, he is committed to that team for that season. Players can be released by the head coach of that team by submitting by email to the Diamond League offices. If a player is released, he may be picked up by another team in the Diamond League until June 30th. After June 30th, no player released from league teams can be picked up by another team in the Diamond League.

13) Each team must carry with them at all times birth certificates of each player along with insurance papers. 

14) Players may only appear on one DL roster with the following exceptions:

a.) Players from a lower age level in the Diamond League (Mickey Mantle division) may be brought up only once to the Connie Mack age level, then back down only once to its original team. 

b.)A player may be brought up an additional time to replace a player that is out with a season ending injury. That player may not be brought back down to the Mickey Mantle division for any league games. 

c.) For organizations with teams in multiple age groups, if a team will have 9 or less players for a game, they are permitted to add enough players to give them 10 active players for the game. 

Any player called up must be reported to the league offices (name and uniform number) and to the opposing team or that player(s) is ineligible.

15)The last day to add a player to a league roster is June 30th of any given season except for injury. After June 30th, If a player incurs a season ending injury, that team can pick up a player to replace the injured player. However, the league must receive a doctor's note with the doctor's name and business phone number. Any player picked up after June 30th is ineligible for the NABF Tournament. After June 30th, no player released from league teams can be picked up by another team in our league.

16) A team/organization that picks up a player(s) for a tournament may not roster that player in the following season. This only applies until the last day of the season.  Exception--Players may be picked up to play in sanction league tournaments such as the NABF and PONY Tournaments.

17a)All members of the Diamond League must practice a positive code of ethics and sportsmanship. Once a player verbally agrees to participate for one team, all other teams shall honor that player's decision.

17b)  Any member of a Diamond League team or organization may not recruit players under contract for the current season.  Organizations with a team outside the Diamond League must honor Diamond League contracts.  Once the Diamond League season is officially over, player contracts are void.

17c)  The Diamond League regular season is officially over on July 6th. Top 4 teams play in the semifinals on July 13th.  Championship game is July 20th.  Player contracts become void at midnight on July 20th.

18)A complete schedule, with Diamond League games highlighted is due at the spring meeting. Failure to turn in a  schedule will result in a $10 fine per day.  A complete schedule must include date, opponent, location, time and (home/away) and also include all tournaments and non-league games. Unscheduled league games will result in forfeit(s). That schedule is official. You cannot postpone or cancel a game unless both teams agree (except for weather/field conditions) or a forfeit will be granted.  If there is no forfeit taken...

18b) A forfeit will be granted if a game is cancelled for non-weather reasons, and the team that was cancelled cannot schedule a make up game within 72 hours of cancellation.  The game does not have to be played in 72 hours, only added to their schedule.  Both teams must be open on the reschedule date and a field must also be scheduled.

18c) If a game is cancelled for non-weather reasons in the last week of the season, it is an automatic forfeit for the team that cancelled the game.  This includes cancelling because of tournaments, etc.  In addition, same day cancellations also result in an automatic forfeit for the team cancelling the game.

19)No league games will be scheduled by phone (with the exception of 2021)!!! All games will be scheduled at the January coaches meeting. If two opponents schedule more than the required number of league games against each other, the earliest time(s) and date the teams play will count as the league game.

20)All umpire fees will be divided evenly among participating teams. Each team must supply two new Diamond League baseballs.

--The team that books and/or rents the field is the home team (including doubleheaders.)  Any fee for a playing facility will be paid by the team renting that facility for the game. The home team is responsible for scheduling umpires and communicating any rainout/cancellation to umpires and visiting team.

21a)Each team must purchase their own insurance. Insurance companies are listed on the Diamond League website. The Diamond League must be named as additional insured. A copy of this must be turned into the league at the spring meeting date.

21b) Each team must complete the Concussion Compliance/Lindsey's Law Form that states each team is in compliance with the Ohio Return to Play Law regarding concussions and each team/organization must complete the Safe Sport Act compliance form.

22)All home games--league or non-league, must be scheduled through a Diamond League approved umpire association. Teams must notify the league officials at the spring meeting which umpire association is being used. A list of approved umpires is listed on the website. The Diamond League only allows high school certified umpires. It is each team’s responsibility to send in your home schedule to the approved umpire association that has been reported to the league.

22b) Only High School certified umpires can officiate a Diamond League game.  Two umpires must be scheduled.  If only one umpire shows, the game may be played.  If there are no high school umpires present, then the game cannot be played nor counted as a league game.

--The league will schedule the Diamond League Tournament.

23)Umpire fees are to be paid before the first pitch of a game. Umpire associations that are not contacted about cancellations and schedule changes will be owed the forfeit fee by the home team. If a game is cancelled at the field by the home team before the first pitch and umpires are present, they will be owed $12 apiece from the home team. Umpires are owed 1/2 the fee through 3 innings of play.  Once the 4th inning begins, umpires will get the full fee.  It is mandatory that two umpires are scheduled for each game. If only one umpire is present, teams may begin play. If only one umpire completes the full game, he will receive $90. ($45 per team.)

--please notify the league if the full fee was paid and the game did not reach the 4th inning and no refund was given. 

24)The umpire is the league official for each game.  Any disputes will be handled through a written report from the umpires of that game. There will be no protests of American League rules. All disagreements will be finalized on the field- with the final decision being made by the field umpires for that given game. Any league rule protests need to be communicated to the umpire at the point of infraction, then filed with the league umpire in chief. Exception--for roster protests only, teams have 24 hours from the completion of the game to protest any unrostered players to the league.

25)American league rules will be played (DH for pitcher only). Teams have the option of using an Additional Hitter which is treated as a position.  The DH and the AH cannot be exchanged.  There is no speed up rule and no re-entry.

--A team must start with 9 or 10 players, but must finish with 8 players.  Any space vacated in the batting order is an automatic out with the only exception is if a player is injured and has to leave the game.

26) The high school slide rule will be followed.  Catcher's equipment must be OHSAA certified.

27) All tobacco products are banned from the field of play. Possession of tobacco will result in ejection from the game.  In addition, the Diamond League has zero tolerance for the use of alcohol or drugs at any and all Diamond League events.

28)  The Diamond League will follow the OHSAA Pitching Guidelines for Diamond League games with amendments on enforcement:

Pitchers shall adhere to the following pitch/rest limitations:

  • Pitch Limit: 125 pitches in a day
  • Days Rest: 0 Days Rest 1-30 pitches
  • 1 Day of Rest 31-50 pitches
  • 2 Days of Rest  51-75 pitches  
  • 3 Days of Rest 76+ pitches  

--A pitcher may finish the current batter if the daily pitch limit is reached during that at bat.

--A pitcher is allowed to pitch in the second game of a doubleheader as long as daily max is not reached.

--All pitches thrown in a suspended game shall count toward the daily pitch limit and the total number of pitches thrown.

--Each team must keep a record of all pitches thrown by each of their players in each game and make this available to the league upon request.

--An opponent must file a protest to the umpire in regards to the pitching rules at the point of infraction for the daily limit.  For the days rest, teams have 18 hours from the completion of the game to file a protest.  Any player pitching after the limit is reached or during a period in which rest is required is considered to be pitching as an ineligible player. (Penalty:  Forfeit)

29)The Diamond League is a member of the NABF and PONY and offers opportunities to play in these high-quality sanctioned tournaments.

30)Playing in the  NABF Regional Tournament also commits your team to play in the  NABF National Tournament if your team qualifies. Forfeiting games in the NABF will result in a suspension and possible fine from the  NABF League offices. Any team that advances in the NABF,   Tournaments will receive a tournament allowance as determined by the Diamond League board.

31)The winning team of a league contest will report the score.  You may text, email or tweet in the score. League standings will be kept by the league director receiving scores on a daily basis. Failure to send in a score that evening or if a late game the next morning will result in a $10 fine. Check the league website for standings and schedules.

32)Teams should email the league with any tournament championships and any top four finishes. They will be posted on the league website.

33)Equipment: League teams will be required to purchase 2 dozen Pronine Pro baseballs through the league for use in Diamond League Contests. BBCOR metal bats or wood bats are allowed.  Teams should carry a medical kit to each game. Catchers equipment must be high school certified.  

34) A high school lineup card must be used for all Diamond League games. Uniform number, name, and position must be listed on the lineup card. A copy of the lineup card must be given to the umpire. Teams are requested to list all substitutes and their numbers on the lineup card. However the official roster is listed on the Diamond League website.  All lineup changes must be reported to the umpire.

35) All personnel on field or in dugout must be listed on the website.  No coaches or players are allowed in the dugout or on the field if they are not listed on the website.  All coaches listed on the website must be compliant with concussion law, Lindsay's Law, and the Safe Sport Act.

35A) All personnel must wear a team uniformed (numbered) shirt. Failure to do so will result in ejection from the field of play. The coaches must wear a uniformed shirt or jacket and pants or shorts that are the team colors. It is recommended that coaches shirts and jackets have a readable uniform number. If a coach is ejected that does not have a uniform number that is readable by the umpire, the head coach of that team in addition to the coach that was ejected will be suspended for one game. Each team is allowed one scorekeeper in the dugout that need not have a numbered jersey.

35B)Players on league rosters can not have the same jersey numbers, players on league rosters on our website must show a jersey number to play in league games, the league prohibits teams from sharing jersey numbers for their league roster. If a league game is played in violation of this rule, a penalty will be enforced by the league.

Coaches and Players are permitted to have the same jersey numbers on a league roster on our website.

36)Any player or assistant coach ejected from a league game must serve a one league game suspension. If the same player/assistant coach is ejected in a second league game, he must serve a three league game suspension. A third ejection by that same player/assistant coach will result in suspension for the season. That player/coach will not be permitted at any league games. A head coach ejected from a second league game will serve a one league game suspension. third ejection will result in a two league game suspension. fourth ejection will result in suspension for the season.

--Any coach approaching an umpire in the parking lot is subject to a two game suspension upon investigation of the incident for a verbal altercation.  Any physical altercation may result in removal for the season. 

37) Any player initiating a fight shall receive a three game suspension. Any team personnel, including coaches, who leave their positions and participate in a fight shall be ejected and suspended for the team's next three league games. A second offense will result in suspension for the season. Exceptions to rule: if a player involved in a fight while remaining at their position on the field is judged to be acting in self-defense. If a player or coach leaves their position and makes contact with their own players/teammates in an attempt to prevent a fight.

38)Any conduct detrimental to the league will subject your team or individual participants (players/coaches) of the team to probation, suspension or possible dismissal from the league.

39) Failure to adhere to any rule will result in forfeit, team/individual  probation and/or possible dismissal from the league.

40)The league fees for the 2021 season are the following:

  • $340 league fee (non-refundable)
  • $120 forfeit fee*
  • League Baseballs ProNine H.S. Pro $55.50 per doz.  min order 2 doz.

41)League fees must be paid by the October coaches meeting. Failure to pay will result in losing entry or reentry into the league.

    -- any fees, including league fees, franchise fees, tournament fees, or baseball money must be paid when due.  Late fees of $25 per month will be assessed at the end of the month and will accumulate at the end of every subsequent month for any unpaid fees.

* Forfeit fees are refundable to non-returning teams the following September.  A team must notify the Diamond League by September 30th to claim their forfeit fees.

**Returning Diamond League Champions pay no entry fee. (they must purchase min order of baseballs.)

© 2021