AIxploratorium
Decision Trees - Page 1

Who will win the game?...

Story

You are in the office pool, currently betting on the outcome of next week's basketball game between the MallRats and the Chinooks. You have to decide which team will win, then bet on that team. Of course, you could just guess, or flip a coin. Here we present a way that (typically) will do better: by using observations about the past performance of the teams. That is...

You've been tracking the MallRats over the season, and recorded various information about the previous games. In addition to the obvious logistics about each game:

• the name of the opponent
• was the game at Home or Away, and
• was the starting time 5pm, 7pm or 9pm.

• Did Fantastic Fred (FF) start the game; or come in off the bench
• Did Joe play center (in the MallRat offense), or did he play power forward.
• Did Joe guard the opponent's center, as opposed to one of the opponent's forwards.
• You also note whether that opponent's center was tall (over 6'9") or not,

• who won the game.

You know, from various reliable sources, that this championship game will be away (not on the MallRat court), at 9pm, that Fantastic Fred will not start, and that Joe will play center on offense, but will not defend the Chinook's 7'1" center. That is, you know:

What you don't know, of course, is who will win this game. Of course, it is reasonable to assume that this future game will resemble the past games. Note, however, there are no previous games that match these specific values -- ie, no previous game was exactly

[Where=Away, When=9pm, FredStarts=No, JoeOffense=Center, JoeDefends=Forward, OppC=Tall].

We therefore need to generalize -- by using the known examples to infer the likely outcome of this new situation. But how?

Your turn

Who do you think will win? ... and why?

Note that the MallRats have split their previous 20 games --- winning 10 and losing 10. So this "overall statistic" does not help. Similarly, they are 4-and-4 on away games -- which also does not help. However, they have lost all 4 of their previous 9pm games, which suggests they will lose this upcoming 9pm game. They have also lost 6 of the 8 games when Fred did not start. However, they are 8-Wins-and-3-Losses when Joe plays center on offense, which suggests they will win this game; and they are [6W, 4L] when the opposing center is over 7'. Or perhaps we should consider some combination: perhaps Joe does a good job defending tall centers, or whatever...

So, if you were going to place a bet, would you bet that the MallRats will win, or not?