Anyone with even a passing passion for snooker (real, virtual or spectating) will soon realise how useful it is to quickly calculate the remaining maximum points value for the balls remaining on a snooker table during a frame in progress.
Let's jump straight to it.
To get a quick answer, you'll need to be up-to-speed on your eight-times (8x) table.
The formula for calculating the remaining maximum points on a snooker table is this:
8r + 27
where r is the number of red balls remaining.
This works because the maximum score you can attain from a red-colour combo is 8 (a red plus the 7-point black ball), and the value of the six colours which need to be potted after all reds have been cleared is 27.
You can see it works straight off at the beginning of a frame:
15 x 8 + 27 = 147
This is the value given by snooker commentators and on-screen captions when they mention how many points are remaining.
It's a maximum value because if a player can't sink a black ball after every red ball (or fails to pocket any colour after a red) the remaining score is reduced.
Here's a lookup table of maximum remaining score, if you don't want to do the maths:
Max score remaining
Current max score
For good measure, here's the table of remaining points when on the last six colours in a frame:
Y G Br Bl P B
G Br Bl P B
Br Bl P B
Bl P B
Of course, this is points remaining for a 'perfect' frame, with both players starting at zero points. If you want to calculate the maximum points remaining from any point in the game, you have to take into account what's already been scored.
To work out how many points can be scored by each player, use the following formulae:
s + (8r + 27)
where s is the player's current score and r is the number of reds remaining..
These work when a player is about to pot a red. If they have already potted a red and are on a colour, the formulae are:
Player at table: s + (8r + 34)
Inactive player: s + (8r + 27)
where s is the player's current score and r is the number of reds remaining.
So now you have a good idea how to work out remaining points, and from there you can work out whether you can win a frame, or should concede, or stick it out for snookers.