OSCO Tournament Rules

General rules & policies

  • OSCO tournaments are run in accordance with the U.S. Chess Federation's Rules of Chess, 7th Edition. The chief tournament director has final discretion on all questions, issues, and disputes.

  • Swiss System. No eliminations! Every player plays all rounds, win or lose. If you have to leave early, be sure to alert a tournament director.

  • One 1/2 point bye available for any round except the last one. Must request in advance and check in with the chief TD following missed round.

  • When possible, pairings are team sensitive; players from larger teams should expect to play each other now and then.

  • Accelerated pairings may be used for over 40 players in a section.

  • The tournament will be run in accordance with the current USCF Official Rules of Chess. The chief tournament director will be the final authority regarding all rulings.

  • Any K-12-aged student may participate in any OSCO tournament. Certain OSCO tournaments may allow college students up to age 21 in certain sections. Only Oklahoma K-12 students are eligible for titles, trophies, and scholarships.

  • Equipment: If you have a chess clock, please bring it to use in the tournament. You will be allowed to use it unless your opponent has a clock with priority according to the USCF rules.

  • Chess boards and sets will be provided for tournament games only. Bring your own sets for skittles.

Before the tournament

  • Make sure your player's U.S. Chess membership is current. 

  • Know the deadlines! Registration for most OSCO events ends at 5 p.m. Thursday just before the tournament. Requests to play up also must be made by this deadline. Cancellations submitted to us by 11 a.m. the day before the tournament will be refunded, minus the processing fee, within 7 days. 

  • One you've registered, visit the Entries page to check your player's registration. Alert us to any questions you have about rating, section, or team code. Entries are updated daily starting one week before the tournament. 

At the tournament (Important for new players & parents)

  • Parents are not permitted to remain in the playing room during games. (A few minutes is usually allowed at the start of rounds for photos.)

  • Cell phones are prohibited during games. If you must bring a phone into the playing hall, switch it off and keep it out of sight. If a player's phone makes a sound, or if a player is observed with a phone during their game, a forfeit loss could result. 

  • Clocks are required in Premier and Reserve. Clocks may be used in any section. A player with an approved clock may use it in their games per U.S. Chess rules, so we encourage all players to become familiar with using a clock.

  • Notation is only required in the Premier section. But we encourage all players to write down their games. 

During the game

  • Touch-move rule: If you touch a piece, you must move it if you legally can. 

  • Touch-take rule: If you touch your opponent's piece as if you capture it, you must do so (if the capture is legal).

  • Once you let go of a piece you have moved, you may not move it to a different square. 

  • Use only one hand to castle. 

  • Touch the clock with the same hand you use to move the pieces.

  • You may quietly say things like "check*," "I adjust" (before adjusting a piece on its square), "Draw?" or to indicate that your opponent has made an illegal move (if your opponent is in check, for example, and makes a move that does not get out of check). Other than that, no talking!

    • *It is not necessary to say "Check." You can, but you don't have to.

  • Communicating with anyone other than your opponent and a tournament director is prohibited. This includes:

    • players at other boards

    • your parent or coach

  • If you need to use the restroom during a match, you may do so. Leave the clock running. The same "no talking" rules apply when you're on a bathroom break, though it is permitted to say "I'm still playing" if someone tries to speak to you. 

  • If you think your opponent has broken a rule, you must report it right away. Do not wait until after the game is over. Raise your hand and wait for a tournament director. 

When your game ends

  • When your match is over, raise your hand and wait for a tournament director to come and verify the checkmate (or stalemate, etc.)

  • Set up your board and go with your opponent to the scoring table.

  • Once you have reported your score, you must leave the tournament room. 

Time controls

All regular OSCO tournament games have a base time control of 45 minutes (G/45 = game in 45 minutes = each player has 45 minutes). Sections labeled d5 include a five-second delay. This means that when one player completes a move and touches the clock, five seconds will elapse before the other player's clock begins counting down.


Section titles indicate the rating threshold players must achieve to move up to the next section. For example, players in a section titled U300 (Under 300) will remain in that section until their rating reaches or exceeds 300 points.

A player’s section is determined by his or her US Chess regular rating and, in some cases, other factors such as an alternative rating, the player's age or school grade, and the rating status (provisional or established).


Alternative ratings
Before 2021, OSCO tournaments were rated by Chess Express Ratings (CXR). Beginning in April 2022, players may choose to play in a higher section corresponding to their CXR rating, but this is no longer required. Requests to play up must be submitted prior to the tournament's registration deadline.

When a player entered in a regular-season OSCO tournament has no US Chess regular rating but has a US Chess blitz rating, the blitz rating is used to determine that player's section. A US Chess online rating is used only when it is a player's only US Chess rating.

Not all sections are solely defined by rating. Some sections may also be limited by school grade. Players with provisional ratings may not be eligible for all sections. We encourage players and parents to read the section definitions for each tournament and contact us if you have questions.

Provisional and established ratings

Players’ US Chess ratings are considered provisional if they have played 25 or fewer rated games (rather than 20 under the old system), and established if having played more than 25.


There are two different formulas to compute ratings. The criterion for using the different formulas depends on whether the player has completed 8 tournament games. The formula for ratings based on 8 or fewer games is called the “special” rating formula, and the other is called the “standard” formula. A provisional rating is updated using the special formula if the number of completed games is 8 or fewer, and the standard formula if the number is greater than 8. Established ratings are based on the standard formula.

for more information about how ratings are calculated, visit www.glicko.net/ratings

Moving to a higher section

  • Rated players: If the player's rating is within 100 points of the next higher section, the player may request to play up to that section.

  • Unrated players: Players who are unrated in all US Chess categories and also have no alternative over-the-board rating (such as CXR) may request to play in a higher section based on an alternative online rapid or blitz rating. In such cases, section will be determined as follows:

    • Player's chess.com rating -200 points​

    • Player's lichess.org rating -250 points

The above rule does not apply to players with an OTB rating (provisional or established in any category). Any exception to these rules is at the discretion of the chief tournament director. Requests to play up must be submitted via email by 5 p.m. on the Thursday before the tournament, or by speaking directly with the chief tournament director the day of the event.



First-place ties
In a tie for first place, if there was a decisive head-to-head result (if the tied individuals played each other and the result was not a draw), that result is used. If there was no decisive head-to-head result, a G/5 blitz match is played to break the tie. If that game ends in a draw, the tied individuals play an
armageddon blitz match: the player with the white pieces gets 6 minutes; the player with the black pieces gets 5 but need only draw the game to win.  

Ties for awards other than first place

If two players are tied and there was a decisive head-to-head result, that result is used. Otherwise, OSCO uses the U.S. Chess-recommended order of computer tiebreaks. These are 1. Modified Median, 2. Solkoff, 3. Cumulative, 4. Cumulative of Opposition. Click here to learn about these tiebreak systems.

Team scores will be the total of the top 3 scores in a section for players from the same team. There must be at least two players from the same school to qualify for a team award. Coaches and Players must verify proper team affiliations and team totals on the posted team standings. Corrections to team affiliations must be made prior to the beginning of the last round and should be checked at the beginning of the tournament for correct team sensitivity of pairings.

School teams
A school team is defined as a group of players that have their primary enrollment in the same school. No combined schools are allowed. A school is defined as the same building or connected buildings under the same name, or a homeschool group of players who do not spend any part of the school day in any K-12 building.

Club teams
To give another option to players whose schools do not have a chess club/team, OSCO allows members of non-school chess clubs to compete for team awards. Club team players/coaches/parents should be aware of these rules: 

  • Club team players must meet regularly and practice together.

  • Club teams must have meeting time and place published online (on a website, Facebook page, etc.)

  • A player may compete with either a club team or a school team, but not both.

  • Only one change (from club team to school team, for example) per academic year is permitted.

  • A player may not compete on a new team for the first time at the state championship.

  • Club teams must register with OSCO prior to competing together at a tournament. Click here to register your club team

  • In order to maintain the integrity of the Club Team definition, players found to be participating in tournaments as a Club Team member but NOT meeting and practicing as part of the Club Team will be subject to a one-game suspension of both the team and player on the first offense and for one calendar year for repeat offenses.

Homeschool teams

Homeschooled players may form club teams; see the rules above. Homeschooled siblings who are not part of a club will automatically be entered as a team.


Each year OSCO selects four individuals to represent the state of Oklahoma in the  Denker National Tournament of High School (grades 9-12) State Champions, the Barber National Tournament of Middle School (grades 6-8) State Champions, Rockefeller National Tournament of Elementary School (grades K-5) State Champions and the Haring National Tournament of Girls State Champions (grades K-12).  Points will be awarded to players in the Premier Section (with the exception of the State Championship, where Barber and Rockefeller contenders will participate in the 6-9 Open and K-6 Open, respectively) at the following qualifying events:


October 30, 2021 at the University of Tulsa

December 11, 2021 at Stillwater Middle School

January 8, 2022 at Independence Intermediate School in Yukon

March 5, 2022 at The Casady School in Oklahoma City


and at the Oklahoma Scholastic State Championship on April 2, 2022 at Jenks High School, at which Barber and Rockefeller contenders will participate in the 6–9 Open and the K–6 Open, respectively, and girls who wish to compete for the Haring will play in an all-girls' section.


The player with the highest total number of points (the sum of their two best OSCO regular-season events + their final score at the state championship multiplied by two) will be the Oklahoma nominee. Participation in the state championship is mandatory. If the Oklahoma primary nominee declines the opportunity to play, then the player with the next highest score will become the primary nominee.


The player must meet all qualifications specified under the USCF rules for the invitational tournaments.  


Female participants may compete for either the Haring or for whichever of the Denker/Barber/Rockefeller is appropriate to their school grade.

Tiebreaks to determine invitational representatives


If points are tied in any of the invitational categories, the following tiebreaks will be used, in this order:

  1. Head-to-head result at State Championship

  2. Head-to-head results at all qualifying events that academic year

  3. A match consisting of two (alternating colors) G/60;d5 games will be held at a time/place TBD.

  4. The final tiebreaker will be an Armageddon match.