The Plus-Minus stat in Lunacy

[Jared Russell]

I've been trying to come up with a good statistic with which we can approximate the aggregate of the various abilities of each robot this season. It is a hard problem because of the many different approaches to this years' game. I think we will see fast scoring bots who falter, and simple drivers that win blue banners. But everyone has one goal in mind: to maximize the differential between points scored and points allowed.

In hockey, there is a somewhat obscure stat called "Plus-Minus" (+/-) that attempts to quantify the disparity between the number of goals a team scores when a player is on the ice (+1 for each) versus the number of goals a team gives up when the same player is on the ice (-1 for each). If a player is +20, then he has been on the ice for 20 more goals for than against.

We could definitely do this for Lunacy. "Plus" is the amount of points a robot scores in a match. "Minus" is the amount of points scored in that robot's trailer. This stat would help you do apples to oranges comparisons (shooters vs. dumpers vs. pushers) to figure out who can score, who is good at avoiding being scored on, etc. With a little cleverness, you can even compute a normalized +/- that takes into account the opponents (a team who faces a lot of tough teams and emerges +5 has done better than a team that goes +15 against cupcakes).

All we would to do is assign a scout to each team in each round. Simply count the number of points scored by and on each team, and fill out a table. Divide the sum of each team's rounds by the number of rounds and you get a "+/- per round" stat that should paint a pretty clear picture about the robot's performance.

Is this stat perfect? Of course not. <G14> will affect the stat, to be sure. And teamwork is not fully acknowledged (e.g. I push this bot into the corner so you can dump into it, but I have scored no points myself). But I think it might be the best - if not simplest - representation (along with Win/Loss records) to score the robots of Lunacy.

How do the scouts of Chief Delphi feel about this? Is this something worth pursuing on a collaborative, cross-regional level?

-Jared