Week 4 OPR

[Nathan Streeter]

Originally Posted by lineskier

OPR is standard matrix algebra and is a published mathematical formula, so when I see different OPRs it makes me a bit nervous. OPRnet may be taking across multiple event's rather than latest events, which would be cause for different values.

Yes, it is disconcerting if people are getting different OPR numbers... But that really isn't the case: Ed's and Bongle's OPR's do match up for each robot for each tournament. The reason why Ed's OPR *World Rank* numbers are different than taking the highest OPR from each team is because it solves a single world-wide matrix. This is great in many ways, but has the (single?) downside of solving for a single OPR from their Week 1 performance to their Championship performance, which is somewhat flawed. That said, I'm not sure what'd be a better way... :-/

Lineskier (Mike?), would it be possible to use the matrices to compute the EMC and ERC? I really like that EMC and ERC use the twitter feeds to break down a Robot's contribution into Minibot and Hostbot, but without the matrices, they just don't have the same accuracy.

Thanks, EagleEngineer for pointing out the typo, I'll try to fix that!

[Bongle]

Originally Posted by Nathan Streeter

Lineskier (Mike?), would it be possible to use the matrices to compute the EMC and ERC? I really like that EMC and ERC use the twitter feeds to break down a Robot's contribution into Minibot and Hostbot, but without the matrices, they just don't have the same accuracy.

It seems like it should be possible to do this.

Let's say you had two variables per team:
OPRMini
OPRMain

Right now, the right-side vector of data for OPR is just a team's total scores because that's all I get out of the FRC match results. Since Lineskier has all the scores divided into points + bonus, he could just solve using minibot-only and main-only. The downside of this would be that you'd have teams with nonzero minibot scores who never had a minibot or never even went near the tower. You could say those teams "helped get their alliance minibot scored", but really it'd be mathematical noise.

[Ed Law]

Originally Posted by Nathan Streeter

Yes, it is disconcerting if people are getting different OPR numbers... But that really isn't the case: Ed's and Bongle's OPR's do match up for each robot for each tournament. The reason why Ed's OPR *World Rank* numbers are different than taking the highest OPR from each team is because it solves a single world-wide matrix. This is great in many ways, but has the (single?) downside of solving for a single OPR from their Week 1 performance to their Championship performance, which is somewhat flawed. That said, I'm not sure what'd be a better way... :-/

The World Rank is a season long overall score of how a team did. If a team went to two events and scored low on the first one and scored high on the second one, the single World Rank OPR will reflect that. It is not meant to show how strong a team is going into Championship. For that I would recommend using latest score which my spreadsheet will calculate in the OPR Results tab by putting -2 in the G2 cell and click the Calc box to run a simple macro.

Originally Posted by Nathan Streeter

Lineskier (Mike?), would it be possible to use the matrices to compute the EMC and ERC? I really like that EMC and ERC use the twitter feeds to break down a Robot's contribution into Minibot and Hostbot, but without the matrices, they just don't have the same accuracy.

Nathan, this has already been done by Team 33. But it was done manually as a one time thing. The data looks interesting. I was going to automate that using the twitter feed but when I heard that there are missing matches and may be even event, I changed my mind. I don't want to spend time on something if the data is not reliable. If anyone is interested in pursuing that, you are welcome to modify my macros. All the macros in my spreadsheet are not protected. It includes all code needed to assemble and solve the matrix for you.

[mwtidd]

Originally Posted by Ed Law

Nathan, this has already been done by Team 33. But it was done manually as a one time thing. The data looks interesting. I was going to automate that using the twitter feed but when I heard that there are missing matches and may be even event, I changed my mind. I don't want to spend time on something if the data is not reliable. If anyone is interested in pursuing that, you are welcome to modify my macros. All the macros in my spreadsheet are not protected. It includes all code needed to assemble and solve the matrix for you.

Nathan was asking about ETC, ERC and EMC which have nothing to do with matrices or OPR. And they are all calculated automatically. I just haven't published the latest version of my site.

Originally Posted by Nathan Streeter

Lineskier (Mike?), would it be possible to use the matrices to compute the EMC and ERC? I really like that EMC and ERC use the twitter feeds to break down a Robot's contribution into Minibot and Hostbot, but without the matrices, they just don't have the same accuracy.

Actually matrices inherently has an equal potential of inaccuracy. Digging through my threads I talk about how my algorithm is actually executed and the resolution it gets over OPR. Matrix algebra looks at the big picture, but it doesn't look match to match. ETC does look match to match. Point inflation affects both in different ways. Also I can tell which alliances finished in which place with minibots. So if someone has an EMC of 30 I KNOW in every qualifying match their alliance put up a winning minibot.

Also I calculate your team's contribution to each match, for the robot. OPR does as good a job as it can using traditional mathematics. I use CS algorithms to calculate my #'s. That being said there are still issues with point inflation that are inherent in any system. Some teams will have the luck of the draw. I have an idea of how to fix this for the ERC but it will take a bit to implement.

If someone had a java function for calculating OPR I could quickly implement it. ETC and OPR look at a teams contribution from 2 separate directions. I believe by utilizing both that the values it will hone in on a team's true contribution.

[IKE]

Originally Posted by Ed Law

Nathan, this has already been done by Team 33. But it was done manually as a one time thing. The data looks interesting. .

When compairing this data to some scouting data, it was reasonably accurrate. It turned into a bit of a "tube scoring" version of OPR. I have also eseen this done with penalty data, and some other interesting factors. We should have some good scouting data from Troy that hopefully we can use to tune the algorithms to be even more representative, and then test them at the State championship.

Like the robot, iterating and progressively improving your scouting and metric based scouting as the season continues helps a bunch.