Here's the historical "ones" place data from April 1st to July 10th:
0 ******** (eight)
1 **** (4)
2 ******* (7)
3 ******* (7)
4 ******** (eight)
5 ***** (5)
6 ***** (5)
7 ****** (6)
8 ***** (5)
9 *********** (11)
Chances based on data:
0 - 8 out of 58 chance = 13.79%
1 - 4 out of 58 chance = 6.90%
2 - 7 out of 58 chance = 12.01%
3 - 7 out of 58 chance = 12.01%
4 - 8 out of 58 chance = 13.79%
5 - 5 out of 58 chance = 8.62%
6 - 5 out of 58 chance = 8.62%
7 - 6 out of 58 chance = 10.34%
8 - 5 out of 58 chance = 8.62%
9 - 11 out of 58 chance = 18.97%
A 9 seems like the best shot with just shy of a 20% chance. Of course I got a 5, though I guess it could be worse (1)!
So based on the data, a 9 has a 1.897:10 chance vs the 1:10 Woot stated.
* Obviously this is only based on about three months worth of data so it's not SUPER accurate. Use at your own risk.