I_Need_D_8 said:This one should be easy, but I suck at math. Say you throw 7 stripes and the 8 ball on the table. What is the number of different patterns you can run, given that the 8 ball must be shot last and the stripes can go in any of the six pockets?
SphinxnihpS said:Easy? this problem is far more difficult than the above. It requires the above just as a function of a much larger simulation.
Throw the 7 stripes plus the 8-ball, plus the cueball on the table and you get a random arrangement that can be expressed but not predicted by the above calculation. Since it can not be predicted, you must now run a simulation of many itterations. Each itteration will produce a different pattern of balls on the table. Now how do we shoot them? How hard do we hit them? Which first, which last? What English, etc, ad nauseum? With only very few variables you could easily construct a simulation that requires eons to run, and far more time to interpret the output. In other words, it's better to just go do it in reality.![]()
Thank goodness there are only six possible angles.randyg said:Einstein equated that there were over 5 million shot posibilities in a 9ft. table....randyg
SphinxnihpS said:NOT EVEN CLOSE!
If we go back to your table with a resolution of 1.2MM, then the expression for the number of possible layouts is1200000^10! This is how many possible layouts you can get in a game of nine-ball. It is a number beyond comprehension. The odds that the subatomic structure of your body were to suddenly resonate at exactly the correct frequency and allow you to simply fall through the subatomic structure of the Earth are far smaller than the odds you will ever see the exact same layout in nine-ball to a sixteenth of an inch resolution.
...going by this math.
The correct equation yields a similar number though. For a pool table with a resolution of 1.2MM slots a ball can occupy, the number of distinct patterns of balls is on the order of 1x10^10,000,000, or 1 followed by 10,000,000 zeros.
Big C said:Thank goodness there are only six possible angles.
SPF,
Chris M.
Your math is wrong. With only two balls there are nearly (23e6)^2 positions and with 10 balls there are nearly (23e6)^10. You are not counting all the possible combinations correctly.I saw this problem long ago when I was somewhat of a lurker here and always wondered what the answer was. I recently remembered it and spent some time trying to dig up this thread. the answer may surprise you!
I used a table resolution of 1/64 inch rather than 1/16 inch to make the answer a little more real world. I suspect that 1/64 of an inch is about the lower limit you can move a pool ball on a clothed table.
But for this problem you must account for the other balls, since no two balls can occupy the same space. So the answer for a table with a resolution of 1/64 inch must subtract the answer for a table with the resolution of one ball.
My table fits about 24 balls end to end on the short rail and 48 balls end to end on the long rail (roughly). This gives 1152 discrete ball positions for any ball to occupy. The 1/64 table is 2.25 (ball diameter) times 64. So the 1/64th resolution has 23,887,872 discrete ball positions.
On the break, any number of balls may go in pockets or off the table. So you may have anywhere from 0 to 10 (nine plus the cue ball) balls remaining on the table after any given break shot.
To figure out 10 ball combinations is relatively easy. 10! x the number of discrete positions for both resolutions, then subtract the lower resolution from the higher resolution.
To figure out anything less is a little bit trickier, but similar.
To figure out all possible combinations requires figuring out all combinations of 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and 0 and adding them all together.
The answer for my table is 87,935,657,238,036, or approximately 8.79 x 10^13. Far less than the OP suggests.
I will consult some books on combinatorics and get back here with a valid solution.
This reminds me of a proposition shot. Bet someone that they cannot make a shot that you will make and you will give them 100 tries. Rack the balls and then break them. Mark where all the balls are and now it is their turn to duplicate it.
Einstein equated that there were over 5 million shot posibilities in a 9ft. table....randyg
I am just here looking for the answer, if someone could help me please.
I am just trying to find out how many different shots I need to practice, if anyone knows please let me know, thank you.:grin:
There is no particular number -- the finer you feel like dividing the table up, the more shots you have. To the best of the knowledge of the interwebs, Einstein made no comment about pool.Someone (BD?) in the past few decades said it was 4 trillion shots.
Jeff Livingston