Four billiards disciplines, four rule systems: why the numbers cannot be shared

On a Thursday evening in mid-January, at a billiards club in east London, I sat between two tables with my laptop open. On the left, a snooker frame: a player made 87 in one visit before running out of position. On the right, a nine-ball rack: a player broke, ran seven balls and closed the rack. The amateur logging software I use to track local events dumped both into a single column labelled break. The next morning the export showed a mean of 43.7 for that column. A young coach messaged to ask whether he could use the figure to compare the two groups of players. He could not, and the reason had nothing to do with sample size. The 87 was a continuous scoring visit on a 12-foot snooker table with six tight pockets. The 7 was a count of balls remaining after a break shot. They shared a column because the software does not know one discipline from another, not because they measure the same thing.

Since that night, the first thing I do with any billiards data file is establish which discipline is being measured, before the tournament name and before the player name. The four most common rule sets in billiards share almost the entire professional vocabulary: break, safety, pot, foul, rack, frame. They differ only in meaning, and different meanings produce different denominators.

The British market reads billiards in snooker

Britain is a snooker market, and that shapes the writing. The three biggest events are grouped as the Triple Crown: the World Championship, the UK Championship and the Masters. The World Championship is played at the Crucible Theatre in Sheffield, with a final staged over 35 frames across two days. The ranking system runs on a two-year cycle, and a tour card is a time-limited asset. When a British newsroom covers billiards, the default vocabulary is century, 50-plus, safety exchange, miss rule, and the word snooker is used as a noun for a position rather than for a sport. Names such as Ronnie OSullivan, with seven world titles and more than 40 ranking titles, shape how the British public understands the sport, and shape the metric set people assume to be the standard.

The money moved outside that frame long ago. Chinese 8-ball, usually called heyball, runs its own circuit with prize funds large enough to pull snooker players across. Gareth Potts, an English player who won world titles in 8-ball before competing professionally on the Chinese 8-ball table, is the clearest example of a career current running from the English table to the Chinese one. American nine-ball has Matchroom as its broadcast base and a global professional circuit. Three-cushion carom has the UMB and a scoring system that shares nothing with the others. Four worlds, four governing structures, four ways of telling a story with numbers.

There is no shared database across those four worlds. Snooker has WST data plus independent snooker-specific archives; nine-ball has figures published by its promoters; Chinese 8-ball runs its own system under the Chinese Billiards and Snooker Association; carom has the UMB. Based on my experience tracking matches across all four systems, the moment of error is not the calculation but the stitching together of those fragments.

Four metric sets that cannot be converted

Snooker uses 15 reds and six colours on a 12-foot table, with pockets around 86 mm. The unit of measurement is the visit. Three pillars are points per visit, pot success and safety success. A century break marks a visit past 100 points, and it exists only in snooker because only snooker has a ball structure that allows scoring to accumulate that way.

American nine-ball uses nine balls on a nine-foot table with far larger pockets, and the mandatory rule is to strike the lowest-numbered ball first. The units are the rack and the break shot. The pillars are pot rate on the break, break-and-run rate, the length of consecutive rack wins off the break, and the handling of push-out situations. A century break does not exist here, and any comparison using one fails at the unit level.

Chinese 8-ball uses 16 balls under 8-ball rules, but on a snooker-sized bed with rounded pocket jaws. That combination produces a hybrid: snooker table dimensions, 8-ball rules, and a potting difficulty well above the American pool table because rounded jaws reject balls that would drop elsewhere. The pillars are break-and-run rate and average visits per rack.

Three-cushion carom has no pockets. There is no pot and no rack in the ordinary sense. The units are innings and points; the metrics are average, run and finishing rate. A carom player averaging 1.5 points per innings is performing very well, and placing that next to a 92 per cent pot success from a snooker player produces a comparison with no meaning.

The three most repeated analytical errors I read all originate here. The first is comparing pot success across disciplines without converting pocket size: the gap between 86 mm and roughly 120 mm creates a systematic difference larger than the skill difference between two groups of players. The second is treating the century break as a universal skill index, when it is a structural speciality of snooker. The third is ignoring variance structure: a snooker frame generates many visits with widely dispersed scores, while a nine-ball rack often ends after a handful of contacts.

The denominator is where the damage shows. In a best-of-7 snooker match, a player may have six to eight genuinely meaningful visits. In a race-to-9 nine-ball match, the number of breaks falls around 9 to 11. Place those two structures side by side and average them into one column, and every rate has had its denominator changed without a note. That is why cross-discipline comparison tables look tidy and support no decision at all.

The final layer is governance. Snooker has the WPBSA for rules and discipline and WST for commercial matters. International pool sits with the WPA. Chinese 8-ball sits with the Chinese Billiards and Snooker Association. Carom sits with the UMB. A sanction in one system does not automatically become a sanction in another; mutual recognition is a separate decision, conditional and time-bound.

The John Higgins case of 2026 is the classic reference point. He was suspended after footage published by the News of the World, was found not to have fixed matches, but was found in breach of rules for failing to report the approach. The penalty was a six-month ban and a 75,000 pound fine. What matters is not the number but the structure: a player can be cleared of the gravest allegation and still be sanctioned for a procedural failure.

In June 2026 the WPBSA announced sanctions against ten Chinese players after a long investigation, including two lifetime bans for Liang Wenbo and Li Hang, and bans of varying length for the others, from roughly 20 months to five years. Cases such as Zhao Xintong and Yan Bingtao show that the length of a ban is data, while whether a player returns to the circuit is a story belonging to each separate governing system.

Where the data starts lying

Sports analytics has a habit of attributing every error to sample size. Most errors I encounter sit one step earlier: misidentifying the object being measured. A billiards data file that does not state its discipline is unusable, however many columns, rows and polish it carries.

There is a less comfortable consequence. When I scan a match data file and find no anomaly, that result says nothing about anyones integrity; it says only that the sample is not yet sufficient. An empty checklist is a null finding, not a certificate. In billiards, where integrity cases usually surface through a sequence of matches rather than a single one, misreading emptiness can harm both the wrongly suspected and the genuinely suspect.

The silence of data, like the silence of an empty arena, is an experimental condition rather than a conclusion. It lets me hear more clearly, but it does not license me to claim I have heard everything. Results are noise; cue-ball paths and the structure of visits are the signal. That signal is only readable when you know which discipline you are standing in.

Data limitations

Format figures come from published tournament schedules and promoter statements; the June 2026 sanctions come from the WPBSA statement; the John Higgins case comes from the public 2026 record. Observations on pocket size and table speed are personal notes from amateur clubs in London rather than measurements at professional events, so equipment error has not been removed. The sample behind the denominator comparison covers only matches I logged directly and is not sufficient to generalise across the professional circuit.

What I will check at the first event of next season

Three things are worth tracking over the next twelve months. The first is how many snooker players move into Chinese 8-ball events, because that is the earliest indicator of the money gradient. The second is whether governing bodies extend mutual recognition of sanctions, which decides whether a player banned in one place can still earn in another. The third is whether anyone builds a cross-discipline index that converts for pocket size and visit structure; without one, every cross-discipline comparison table should be read as a game rather than a conclusion.

Next season I will start every data file with a single note at the top: which discipline. Everything else only means something after that line.