correction: an extra "5-8" listed under "13".
KY Floyd,
Thanks for reply and analysis to post.
I counted 24 instances of 7 and 19 of 8. Did I miss any?
Coin Count after corrections.
1. 18
2. 19
3. 27
4. 27
5. 27
6. 24
7. 24
8. 18
9. 16
Unless you think there's a reason to draw multiple coins I'd simply draw a single coin, or at least record them as individual selections instead of sums. There are more combinations that add up to 9 than 2 and 17, but sums don't win.
I listed the draws as combinations or sums to see if any unusual patterns occured. Sums don't win but if the machine has a bias, the bias may produce more combinations with a sum of "10" in this 2/9 lottery or more combinations closer to "143" in a 5/56 lottery.
Whichever one is selected the first time has a 1 in 9 chance of being selected in subsequent selections, so you would "expect" it to be selected again in selections 2 through 10.
OK. What happened last has just as much chance happening again.
Finally, what makes you think the experiment has been conducted thousands of times with the same results? I'd guess that most times it may have been done the results had a pattern that was similar to yours, though the individual numbers would be different.
My hyperbole. "7" is lucky in the West, "8" is lucky in the East. Just wondering how all that got started.
Opinion: Lottery Ball Drop Machines may be at their physical limits when producing five number lottery combinations such as 1-2-3-4-5 or 52-53-54-55-56. A machine with average abilities can produce combinations near the middle of "range of sums" with little problem. Better design machines can produce combinations near the low-end and high-end of the range of sums easier.