CueLab / Safety & Defence
Most amateur players underrate safety play until they reach a certain level — then it becomes the difference. These six tools give you numbers for the parts of the game that have always been on the edge of "feeling": how risky is this safety, how trapped am I really, where will the cue ball end up if I play stun with a touch of side.
Press "go for the safety" or "play safe and let them in" is a decision coaches often see made on gut. CueLab gives a structured score from 1 (almost sure to leave opponent in) to 10 (almost sure to leave them in trouble). It weights your normal safety success, the visible cue-ball-area for the opponent, and whether there is a path back.
Higher score = higher risk that this safety hands the initiative back. A score of 3 or below is "play it" territory; 7+ is "consider attacking instead". Use it as a second opinion, not a verdict — snooker safety decisions often involve tactical reads the calculator cannot see.
There is no good model for "how good a safety player is" because it varies enormously by shot-type and table-condition. We use a published mid-range figure as the baseline and assume the rest is conditions, not skill delta.
A common modern rule interpretation: a referee can call "miss" only if there is no reasonable way to strike the ball on, even via multiple cushions. CueLab lets you input a few key distances and decide whether the position is "obviously playable", "borderline" or "likely to draw a 'miss'" under modern officiating.
"Borderline" is the dangerous zone: ball is just out of straight-line reach, with one cushion available. Tournaments are full of these and the modern call ("miss" only if escape is genuinely unreasonable) tends to favour the escape. Older rulebooks and stricter referees might call differently.
Refereeing judgement is genuinely subjective — the rule change in 2015/16 was specifically to reduce how often it was invoked. Two referees can score the same position very differently. Use as a planning aid, not a prediction of what your specific referee will do.
Adjust a probability of leaving the opponent in trouble by difficulty (1–10) and table state. This is a generalised version of the safety risk evaluator that you can use to keep a personal log over time, e.g. "every safety I rated difficulty 6, I successfully left the opponent in trouble X% of the time".
When you walk up to the table snookered, the question is "is this worth playing for, or should I take my points and go back to my chair?" This scorer gives a 1–10 score weighted by snooker severity, distance to escape cushion, and the positional cost of any escape attempt you can see.
A score of 6+ usually means the escape is not worth the foul risk in a tight frame. Scores 8+ have a real chance of being called "miss" — especially if you don't get a clean contact.
Doesn't model spin effects. Side spin and screw can rescue an escape that pure stun would fail. If you're a confident swerver, take the lower of two scores.
Pick a stun / follow / draw / side combination and a contact angle. CueLab draws the cue ball's predicted natural-angle path on an SVG mini-table. Real cue-ball deflection is more complex, but this is a calibrated approximation — useful for thinking out a position play before committing.
The natural angle (centre ball) follows the rule of thumb "equal angles in = equal angles out" measured from the tangent line. Follow and draw shift the apparent angle because cue-ball spin persists. Side both shifts and curves the path.
Real tables also throw a few degrees due to nap (cloth weave direction) — we don't model that here. For prediction against a known throw table you must subtract 1–3° from the displayed angle.
After a foul and snooker, the incoming player nominates a colour as a "free ball" — it acts as a red for value but is spotted afterwards. This tool ranks which colour is best to nominate based on the table state, and estimates the extra points a successful free-ball adds to the break.
The free ball adds 1 point (for the nominated colour) + the colour chosen after the next red. So a "green-then-black" free ball adds 1 + 7 + 1 (red) = 9, but the value for break building is that the chosen colour remains on its spot and continues to be available later.
The most valuable choice isn't always the highest-value colour — potting pink first can leave the table open to an opponent safety. CueLab can't model where the balls will end up; it ranks by point contribution only.