The game itself is very easy once you work it out. It's simple math. Here's a tip: count back from one bone. A teeny weeny bit of celebral activity, and you'll beat him.
Note that the "Win a game of Bones" achievement does not have any "sequels". You only get the glory for beating him once.
Here's the solution to bones:
30- Pick 1 bone, making it 29 No matter how many he takes, the next Number you need to get the pile to is 25. Now, the next Number you need to get the pile to is 21. Then, the next Number you need to get the pile to is 17. Then, the next Number you need to get the pile to is 13. Then, the next Number you need to get the pile to is 9. Then, the next Number you need to get the pile to is 5. Finally, take enough to get the pile to only 1 bone. it works if you follow it :]