Board Bulletins

This page contains information and analysis on a variety of topics. It is intended to help club management committees understand the data underpinning your student sport federation’s policies and regulations.

About weight division mergers

Two sparring disciplines are contested in BSTF BUCS taekwondo: WT rules sparring (Olympic rules, full contact) and ITF rules sparring (semi contact). Each, by default, has 8 male and 8 female weight divisions, for a total of 32 weight divisions across both disciplines. Furthermore, BSTF BUCS competitions divide competitors into 3 proficiency classes (A, B and C class) for a total of 96 unique Weight & Class divisions.
BSTF has delivered sparring matches in the tens of thousands over its decades of competitions since 1986, with an adjacent division merger policy being applied where divisions have low athlete populations. This has provided as many athletes as reasonably practical appropriate divisions of competition, competitive divisions of competition, and enhanced development opportunities from the variety and number of competitors and matches in competition.
Competition rules for BSTF BUCS Taekwondo competition, 2018 – present day, stipulate that adjacent weight categories be combined where there are less than four competitors in a division. Where applicable, this generates a new division with the lower of the adjacent division’s minimum weight and higher adjacent division’s maximum weight limits applied to its competitors. In practice, this is identical or directly analogous to the creation of the respective Olympic taekwondo weight division from its two World Championships weight divisions of origin.
Algorithmically, the fewest mergers in a division are made to satisfy the division population rule. Where no directly adjacent weight division with competitors exists, no merger is made.
Adjacent division mergers are standard practice throughout the majority of amateur domestic taekwondo and other martial art competitions
Adjacent weight division mergers are applied in BUCS Karate
Adjacent weight division mergers are applied in BUCS Judo
Adjacent weight division mergers are applied by default in the Olympic Games Taekwondo competition
Defined weight divisions of competition, in combination with strictly applied weigh-in regulations and professional grade and calibrated scales, determine precisely an athlete’s own weight, and therefore the maximum variance between themselves and other competitors within any bounded division.
Unlike non-weight mediated contact sports like rugby, data such as the maximum weight variance between taekwondo competitors in bounded divisions is known in advance to organisers, athletes and their coaches.
In combat sports like boxing and taekwondo there also exist unbounded divisions (i.e., those divisions with all competitors below n_mindivmax kg and above n_maxdivmin kg; for the Olympic taekwondo male weight divisions these are the -58 kg and +80 kg divisions; here, 2 of the 4 male weight divisions of competition are unbounded in their minimum and maximum permitted weight, respectively).
It is feasible an athlete in an (unbounded) heavyweight division might face an opponent e.g., 30+ kg heavier than themselves. It is a vital responsibility of the athlete’s coach, in concert with their athlete, and for all weight divisions, to continually assess their athlete’s ability to perform in their division of competition.
In any taekwondo competition, coaches are able to withdraw their athlete before, or at any point during a match. Such withdrawals are applied by coaches when they are aware/ become aware of a significant difference in skill level between their athlete and the opponent. If a skill difference is too high for their athlete to productively learn from the match and or protect themselves appropriately, it is the responsibility of the coach to withdraw the athlete.
In any taekwondo competition, athletes may withdraw themselves at any time
A statistical analysis of the 2024-25 season’s Autumn and Winter Championships was conducted to determine if adjacent weight division mergers provide any advantage to either sub-set of sparring disciplines’ athletes. The win to loss ratio for matches contested between athletes of a merged division, where one athlete made weight for the lower and directly adjacent weight division before it was merged, and the other made weight for the higher and directly adjacent weight division before it was merged, were segmented from dataset of all sparring match results. 115 matches were contested with these criteria. The data reveal that 57 matches (49.6%) were won by the athlete who made weight for the lower weight division before it was merged, and 58 matches (51.4%) were won by the athlete who made weight for the higher weight division before it was merged. Of the 50 merged weight divisions across the 2024-25 BSTF BUCS Taekwondo Autumn and Winter Championships, 25 divisions (50.0%) were won by an athlete who made weight for the lower weight division before it was merged and 25 divisions (50.0%) were won by an athlete who made weight for the higher weight division before it was merged. These data suggest that, at this level of competition, there is no average statistical match win rate advantage or disadvantage between sparring athletes populating adjoining weight divisions. Raw data for this analysis can be fully derived from the published results online.
Various modern combat sports apply different numbers of and different ranges of weight divisions. Within individual combat sports, these numbers and ranges have also changed over time. For example, the International Judo Federation has changed from a single (open) weight division in the 1950s, to 3 weight divisions in the 1960s, to its present 7 weight divisions for male and 7 for female competitors in the Olympic Games. The number of divisions may vary between genders, for example in the 2020 Olympic Games there were 8 Olympic boxing male weight divisions and 5 female divisions. The number and range of weight divisions may vary between the type of tournament within a combat sport, for example there are 8 male and 8 female weight divisions in World Taekwondo World Championships, and 4 male and 4 female weight divisions in all World Taekwondo Grand Prix circuit events, Grand Slam competitions and in the Olympic Games taekwondo competition, composed of merged divisions from the World Championships format; similarly, the World Karate Federation utilises 5 male and 5 female weight divisions for its World Championships, but employed 3 male and 3 female weight divisions in the 2020 Olympic Games Karate event (male -67 kg, -75 kg and +75 kg, and female -55 kg, -61 kg and +61 kg) by merging the world championship format’s two lowest and two highest weight divisions into the highest and lowest Olympic divisions; similarly, the International Boxing Association’s (IBA’s) 13 male and 12 female weight divisions for World Championships bouts are merged together to form the 8 male and 5 female divisions contested in the Olympic Games. Some combat sports have a maximum bounded upper weight division (the Olympic wrestling men’s freestyle division heavyweight division has a maximum weight in the heaviest division of 125 kg) while some other Olympic combat sports have a unlimited upper weight division (the Olympic boxing men’s super heavyweight division holds all athletes of 91 kg and above; similarly the Olympic taekwondo men’s heavyweight division holds all athletes of 80 kg and above). Different combat sports have different absolute ranges of weight being divisioned across all their fully bounded divisions, for example the lowest and highest Olympic boxing male weight divisions are -52 kg and +91 kg respectively, while the lowest and highest Olympic taekwondo male weight divisions are -58 kg and +80 kg respectively. Different combat sports have different ranges within their bounded weight divisions, with ranges that tend to increase as the maximum division weight increases, for example: Olympic taekwondo’s male -68 kg division spans 10 kg (58 – 68 kg) while its -80 kg division spans 12 kg (68 – 80 kg); Olympic boxing’s female welterweight division spans 6 kg (60 – 66 kg) while its middleweight division spans 9 kg (66 – 75 kg); Olympic freestyle wrestling’s male -86 kg division spans 12 kg (74 – 86 kg) while its -97 kg division then, in a break from the common pattern, spans 11 kg (86 – 97 kg), and finally its 125 kg division spans 28 kg (97 – 125 kg).

About weigh-in regulations

Weigh-in rules exist to protect the safety of competitors in a weight mediated combat sport. For this reason, you will find extremely similar rules are applied by all IOC recognised combat sports and major multinational bodies regarding the operation of weigh-ins.
The competition rules, including weigh-in rules, are published in advance on the BSTF BUCS Taekwondo competition rules and regulations page
The competition rules require that all adult competitors weigh-in wearing only underwear (men: underpants, women: underpants and bra) to ensure an accurate reading. The most accurate body-weight measurement possible is required to confirm each athlete meets the minimum and does not exceed the maximum weight permitted for their division of entry. If an athlete fails to make weight for their division of entry they have the option to change their division of entry, to the one matching their bodyweight, at the weigh-in and accreditation session.
The same weigh-in rules are stipulated in World Taekwondo’s rule set (article 9.3)
The same weigh-in rules are stipulated in International Judo Federation’s rule set (section 6.3)
The same weigh-in rules are stipulated in World Karate Federation’s rule set (appendix 13)
As listed in the weigh-in rules, clothing worn for medical or religious reasons may be worn but will be examined by the weigh-in operators to confirm this has no material impact on the competitor’s weight
As listed in the weigh-in rules, to protect the privacy of the competitors, weigh-ins are conducted in closed spaces, and supervisors and assistants shall be of the same sex as the competitors. Additionally, a privacy screen is available.
As listed in the weigh-in rules, competitors may request the weigh-in room be emptied of all personnel except themselves and the weigh-in operators before completing their weigh-in.
As listed in the weigh-in rules, competitors must not remove their clothing until they are in the weigh-in room. Sports clothing, boxing style dressing gowns or similar may be worn while waiting for weigh-in but shall be removed before stepping on the scales.
As listed in the weigh-in rules, athletes may attempt to make weight an unlimited number of times during the registration period(s), but must re-join the queue for the weigh-in room each time.
As listed in the weigh-in rules, all accreditation and weigh-in desks operated by members of the same sex. BSTF personnel must work in pairs or greater, and are not permitted to operate weigh-in desks alone.
BSTF’s event safeguarding lead oversees the operation of weigh-in and accreditation desks. Any safeguarding concerns may be reported to the advertised event safeguarding lead, or via the BSTF safeguarding report form.
A weigh-in desk may be temporarily closed, with the event safeguarding lead confirming all participants are fully clothed, if an official or technician is required to attend e.g., an equipment malfunction.
BSTF uses advanced Adam Equipment CPWplus scales that are significantly more precise than domestic scales. An Adam Equipment calibration weight is used to calibrate these scales. A maximum -/+50 g variance allowance for players being under/ over their weight division at the weigh-in which is strictly applied.
Given the potential dangers associated with varying methods of reducing body mass in all instances student athletes should seek professional guidance from either a registered dietician or SENr registered sport nutritionist where possible. Coaches and athletes are encouraged to attend our Strength and Conditioning for Taekwondo Athletes Course which includes an athlete nutrition and weight-making module, where guidance is provided by our course leader Dr Carl Langan-Evans, a researcher in the field of safe and effective body mass loss for combat sport athletes.
BSTF recommends that coaches and athletes adopt an evidence based approach, monitoring their athletes’ weight over time and plan for competition well in advance. Penalty fees for weight division changes are in place at BSTF BUCS Taekwondo Championships events to encourage forward planning and discourage inaccurate weight division entries.
BSTF recommends that club committees and contracted coaches improve weight monitoring and selection such that no division changes at weigh-in need occur
At present levels of weight division changes, it takes around two hours to process division changes and re-calculate the competition draw at any given BSTF BUCS Autumn, Winter or Spring Championships. Therefore, it is essential to put in place a disincentive to inaccurate weight division entries, to protect our tournament participants from associated delays and overruns.