CueLab / Break Building
Break building is half geometry, half arithmetic. These six calculators don't pick your shots — they put a number on what's still mathematically available, what's plausible in your hands, and where a frame can quietly leak 30 points if a red-and-colour pair is missed.
Given the balls remaining on the table — reds, colour counts and free-ball status — what is the largest break the player at the table could theoretically construct? We separate "147 maximum" from "given this state, what's left" because conflating them is one of the most common errors in published snooker calculators.
"Strict" is the answer a snooker coach would give if asked the question on a piece of paper assuming every ball was potted. "Maximum available" adjusts for the human reality that even World Champions miss pairs — drop one red+colour pair and you lose 16 (8 + 1 colour of your choice at 7 if black was last). The free-ball toggle treats an extra red as available at the start.
This tool assumes optimal position for every subsequent shot. Real clearance depends on table conditions, the player's position play and whether colours can be visited in a sensible order. Use this number as a ceiling, not a forecast.
Most "clearance planners" online just multiply 8 × reds. This one tells you which sequence is mathematically lightest for position, and flags the sequences that require you to cross the table on the next shot — useful when the balls are scattered and you have to choose between taking reds from one end or balancing the trip.
The default preference is "stay near your current end and clear locally before crossing", because each crossing forces either a longer pot or a positional screw that costs 5–10 cm on the next shot. Crossing the table once is normal; crossing three times is where sessions end.
This does not know the exact ball positions on the table — only which broad half they sit in. For a precise plan you still need to read the table.
A simple Monte-Carlo simulator that runs N attempts with a per-shot success rate you set. It treats a max-break attempt as a sequence of red+colour events plus the 36-point colours, adjusting for the chance that any given red is followed by a black, pink or another colour.
The simulator assumes each red is followed by a colour of your choice (with a "pots black" weight), and that the colours are then potted in sequence. Higher red+black consistency dramatically increases the 147 chance: doubling your skill from "weekend player" to "county-level" often changes the answer from 1-in-100,000 to 1-in-1,500 per visit.
Position play isn't modelled — it assumes every missed red & colour doesn't punish you and that balls remain on their spots. In real play, missing one early red typically reduces your 147 chance by 70%+ because of position. Treat the output as upper bound.
In a frame that comes down to the colours, you might end with a choice: pot the final black and win, or play safe and push it to a respotted black. This calculator gives the implied probability of potting across distance and angle, adjusted for what you normally pot in practice.
Type in a past break — say "15, 1, 15, 1, …" or the shorthand "15×6, 1×6" — and we break it into "reds+black", "reds+other colours" and "colours-only" sections, then rate how efficient the break was vs theoretical maximum with the structure you entered.
Quick examples (click to load)
Total of 15 entries must equal points already scored; "27" represents the 36-point colours run.
"Efficiency" is the actual break divided by the maximum break possible with the same number of reds and colours. A break of 87 with 8 reds+colours remaining caps at 8×8 + 27 = 91 — efficiency 96%. Decent. The point of the metric is to spot quiet leaks (pot a colour after a red, then forget which colour, etc.).
The analyzer doesn't know whether a ball was potted deliberately or as a fluke. A "lucky" pink after a missed black counts the same as one shot. For coaching you still want a video review.
Different from tool #1: it tells you what the *combined* probability of clearing every ball from this state is, given your per-shot success rate. It uses a simplified binomial model so it's transparent, but it lets you see where small changes in skill change "yes" to "no".
The "skill tilt" panel shows how much extra clearance % you'd gain if you improved red-potting by 5 points, or if your colour-from-spot went up 5 points. Generally the colour-run is the easier thing to practise — for many amateurs this is the single biggest gain.
Real clearance is rarely "red, colour, red, colour" straight through; you often need a screw-back to a long red at some point. This model assumes every red+colour pair can be visited without positional aids. Use the result to scope risk, not to plan exact shots.