Weishaupt, A binary search tree and a game tree are not the same thing. On a game tree, you start with the current position as the tree root and all the the possible positions after the next players turn are children of that node and the positions after those positions are children of them. Ex:

```
current position // player 1's turn
/ / \ \
o o o o // player 2's turn
/|\ /|\ /|\ /|\
o o oo o o o o oo o o // player 1's turn
```

Each o is a positions resulting from one of the players possible moves. Off of each of the o's, there are more and more positions until you stop the search tree. This in combination with a min-max algorithm can be an effective way to program an AI for a game like Chess or Tic Tac Toe. A binary search tree is very similar to this, in that it is a tree, but very different in it's use and implementation. A binary search tree is used for sorting and searching. Each node can only have 2 children, a left and a right child. The left child of a node and all of it's children must be smaller than the node and the nodes right child and it's children must be larger than the node. Ex:

```
4
/ \
2 6
/ \ / \
1 3 5 7
```

The root, 4 is the middle value and every node to the left of it is smaller and every node to the right is larger. This makes preforming a binary search extremely easy, just start with the root and compare it to the value being searched for. If the value being searched for is the same as the root, then the search is over. If it is larger then search the tree to the right of the root, otherwise search the tree to the left of the node and repeat until the value has been found or the end of the tree has been reached. This is considerably easier to implement in TI-BASIC because you can represent a binary search tree with a single list, but it is not much use for creating a game AI.