paper: 2010 Team 1114 Championship Scouting Database

[Karthik]

Originally Posted by Drivencrazy

FIRST off Karthik thanks alot. This is by far one of the most proffessional scouting databases I have seen.

Can you tell me where the Calculated Contribution comes from or point me to a forum that does?

Once again thanks and good luck at the champs.

This is explained in a few other places on these forums, but it's probably best that I put an explanation in this thread.

Going into an event like the Championship, it's impossible to watch video on all 344 teams. So, how can you get an idea of what each team's scoring potential is? Well, one way to do it would be just to look at their average score per match. Nice and simple, but it only tells you a small part of the story. Since FIRST matches involve alliances, an average score does not isolate the individual performance of a given team. So if Team XYZ repeatedly plays matches with great teams, their average score will not necessarily be an accurate indicator of the team's performance.

So, how do we isolate the impact of a single team on a match? Simple, using good old linear algebra. For those of your familiar with advanced basketball statistics, the method I'm about to describe is very similar to "adjusted +/-". Adjusted +/- has become a very popular tool among NBA franchises to try and figure out just how much each player is contributing on the court. NBA teams have long figured out that just looking at how many points a player scores does not always tell you how much they've impacted a team towards victory. There have been some great papers presented about this at the MIT Sloan Sports Analytics Conference.

So, here's how it works. For each alliance during qualifying matches at a regional, we set up an equation. Say Teams i, j, k were on an alliance together and scored s points. Out equation would be

T_i + T_j + T_k = s

where T_i, T_j & T_k are variables representing those teams. So if there are m teams at a regional, and n matches, we now have equations that give us a m x 2n matrix. We then solve this matrix for our variables, and voila you have each team's Calculated Contribution.

Why is Calculated Contribution so valuable this year? Well, consider a team that plays the midfield and is great at supplying balls to the home zone, but rarely scores them. If your scouts are just tracking goals scored, they might get a big zero. But their Calculated Contribution (if run over a large enough sample size) would should a higher value reflecting the points they helped their alliance score.

There are a lot more subtle details as to why Calculated Contribution is a good tool, and even more that expose some shortcomings. Unfortunately it's a bit much to go into on CD post while I'm eating lunch. I'll talk a lot about this at my Effective FIRST Strategy Seminar in Atlanta.

Hope this helped.