The easy part:
The dumb AI has an average score of 8.291 for 1000 random words from my large dictionary. The standard deviation of the scores is about 2.15.
The hard part:
We're now waiting on the smart AI to go. It's going to be hard to predict its time, since the AI kicks in when the dictionary size goes below 1000, and the first number below 1000 could be 900, and the first number below 1000 could be 200, and those are vastly different times. I'll feel confident making an estime when I get home tonight, once it's had 8 or 9 hours to run.