Re: Offensive Power Rankings for 2008
 

AMEN!!:D

Re: Offensive Power Rankings for 2008
 

I'm apparently missing 4 teams, which means that there is some regional that sent only 4 teams that I don't have in my data. I'm guessing the Israel one.

OPR of teams going to the championship event. Qualifying matches at all regionals.
Go check out Travis Hoffman's post a few down, he added position numbers to my more-raw post.

Beware that this post includes all of a team's matches all season. 1114's OPR steadily increased from MW to GTR, and ended up at 80+ at GTR. I'm sure most multi-regional teams did as well.

Re: Offensive Power Rankings for 2008
 

sweet! we cracked the top 50!!

Re: Offensive Power Rankings for 2008
 

Re: Offensive Power Rankings for 2008
 

lol, cracked the top 90!

Re: Offensive Power Rankings for 2008
 

i think we now know why its no wonder that whenever 1114 and 2056 got together, there were a lot of points scored:ahh:

Re: Offensive Power Rankings for 2008
 

Since teams such as 1114 are not going to back down to their older OPR's can you post one that only includes the last regional of each team.
I know it could be challenging to set up the program, but it would be a great tool

Thank You

Re: Offensive Power Rankings for 2008
 

Alright, I have thought of a way to do that without too much pain. I should have it done in an hour or so.

Re: Offensive Power Rankings for 2008
 

Thank You!

Re: Offensive Power Rankings for 2008
 

You have the Israel teams.

It looks like you are missing 858, 1254, 2335, 2337, and 2604. Looks like 4 of them all went to West Michigan.

Re: Offensive Power Rankings for 2008
 

West michigan has funnily-formatted results on usfirst.org, and I haven't adopted mine to run on TBA CSV dumps. That's my guess. It's in my list of regionals, but even these updated ones don't include those teams.

Anywho, find attached an XLS file detailing:
-A team's regional count* (I may have missed some regionals due to formatting funniness)
-A team's last OPR
-A team's last regional
-A team's best OPR (if it differed from their last, which didn't happen much)
-A team's best regional

Note that some regionals still don't have all their results up, so for those regionals (Peachtree and one other) the OPR will not be 'accurate'.

oprChamps has only teams attending championships.
oprAll has all teams.

Re: Offensive Power Rankings for 2008
 

Even if you don't use TBA CSV dumps, the data on TBA is formatted very cleanly in HTML tables that ought to copy-paste well into Excel or what have you to turn into good data.

Re: Offensive Power Rankings for 2008
 

You make a good point.

Now includes western michigan regional. oprChamps now includes 333 teams, just like it should.

Re: Offensive Power Rankings for 2008
 

There seems to be a massive discrepancy in the the championship OPR you posted early today and this one. For example, in the first on our team (573) had a OPR of 22.3 and ranked 88th. This one the OPR is 20.2 and we rank 125th. Would you care explaining this discrepancy to me?

Re: Offensive Power Rankings for 2008
 

Which regionals did you attend?

Edit: I have discovered you attended pittsburgh and glr, and here is my theory:
-The new listing only ranks you based on your performance per-regional. The old listing was based on a team's total performance over all of its matches throughout the season. Through the magic of mathematics, your team looked a little better when the overall performance of every team was factored in.

So just like teams like 1114 who improved massively regional to regional get a big boost in the new listing, other teams can actually suffer. Although keep in mind that according to the best OPR listing, you're 115th, because your performance at pittsburgh was better than that at GLR.

Re: Offensive Power Rankings for 2008
 

Pittsburgh and GLR. You did point out the difference in the two OPRs (Pitt was 21.6 and GLR was 20.2) But that still doesn't add up. And apparently while our numbers went down, other teams went up from what they were.

Re: Offensive Power Rankings for 2008
 

Yeah, teams going up is to be expected. Think of a team like 1114, who steadily (and massively) improved their performance from regional to regional. This most-recent listing is ranked by a team's last regional performance, which is very often their best regional performance. A team that did very well at their last competition but poorer earlier would have ranked below you in the earlier rankings (which were based on the whole field of robots at once), but would be ahead of you in these rankings, because these are ranked off of a team's last regional performance, like people requested.

Re: Offensive Power Rankings for 2008
 

I like the new OPR of the last regional attended, due to the fact that it is more indicative of a team after adjustments to driving, strategy and robot features were made after attending more than 1 regional.
Our biggest feature change was moving our pneumatic piston to our claw which pops balls over the overpass once our claw opens.
We sacrificed popping balls during hybrid and moved it to our claw instead.
With increased speed, hybrid adjustments, and improved driving, we went from doing 1 or no lines in hybrid to now being able to consistently doing 4, with much greater speed, and hurdling capability.
Its too bad it took 3 regionals to figure it out, but at least we will be much better prepared for CMP.
On another note, its funny how us and our favorite Hawaiian teammate are ranked next to each other, off by a few decimal points.:D

Re: Offensive Power Rankings for 2008
 

I just got an interesting idea.

I have scouting data for matches from Friday at the Wisconsin Regional for every team. However, the power rankings are for every match.

Could someone please figure out the power rankings using only Friday's Wisconsin matches for comparison?

Re: Offensive Power Rankings for 2008
 

Re: Offensive Power Rankings for 2008
 

Oh thats it, so the first one was an overall OPR and the last one was based only on a teams last performances? Gotcha.

Re: Offensive Power Rankings for 2008
 

My data was determined using actual scouting. Scouting was done by 2194 and 171. I have the data for every team if you want me to compile it all. This is only for Friday at Milwaukee for comparison.

Kind of interesting to see the differences.

Power Rankings
Actual

Re: Offensive Power Rankings for 2008
 

Can you post San Diego?

Re: Offensive Power Rankings for 2008
 

Nice job on the stats all of you who have been working the numbers...a thought has occurred regarding use of last regional numbers to rank teams-a stated presumption of best performance then if multiple regionals were entered doesn't take into account factors like some regionals with a higher proportion of rookie teams (translating often into higher scores by veteran teams) which was seen in Hawaii last week and Okla and Minn. earlier. Also, increasing levels of defense have shown up in some of the latest regionals as the game evolves (watch footage from LVR). Seems like an average of all performances is more representative...and the likely data source my team will use for some assistance with early scouting.

Re: Offensive Power Rankings for 2008
 

Too bad FIRST doesn't report penalties. I wonder how those are affecting these results.

Re: Offensive Power Rankings for 2008
 

Well, the head ref records penatlies for each robot during the match on a sheet, but you never see it unless you go to the "Contest the score" box.

My data comes from Lines Crossed in Hybrid, Balls Removed in Hybrid, Laps, Herds, Hurdles, and Balls Placed at the End.

Re: Offensive Power Rankings for 2008
 

Like 171/2194, 1732 recorded the amount of points a team scored per match at Wisconsin. We kept track of lines and balls knocked down in hybrid, laps, hurdlers, herds and balls placed at the end.

I ran a correlation test to see how related the two sets of data are and see how good the OPR is at predicting how many points a team scores per match. There are some assumptions/problems. First, our scouting data isn't perfect so there is some error from that. Secondly, our scouting data doesn't include penalties, but the ORP does account for them. So, when doing a linear regression, I got an R value of .7841 and an R-squared value of .6149. (A perfect relationship would have an R value of -1 or 1 and no relationship would be 0). So, while it is not pefect (not surprising) the ORP is a fairly good predictor of a team's preformance.

Re: Offensive Power Rankings for 2008
 

I agree. The OPR does do a pretty good job. Of course, hard data is nice too, but I find it really awesome that you can figure this much out with just match scores.

Re: Offensive Power Rankings for 2008
 

One reason for Offensive Power Rankings not matching reality is due to the fact that OPR’s are based on the averages of partners’ OPRs rather than actual contributions. Any deviation of a team from its ‘average’ contribution in a given match will always erroneously drive their partners’ OPR up or down.

These deviations can be large; it would not be unusual for a team to contribute 20 points in one match and then perhaps due to penalties, “contribute” -20 in the next. Given enough matches one might expect these errors to cancel each other out. However, when there is a limited number of matches (think: 8 coin tosses don’t always produce 4 heads and 4 tails) and the high degree of volatility, the error can be significant.

So while the OPR may be a good predictor, there's still no substitute for accurate, detailed scouting!

Re: Offensive Power Rankings for 2008
 

Spot on John. Congrats on the Woodie btw. You deserve it. Hope to catch up with you in Atlanta.

Re: Offensive Power Rankings for 2008
 

I asked this question earlier, but no one replied to it:

if there was a normally very high scoring team that happened to malfunction in a match where they were in your alliance, or was defended a lot in your particular round, wouldn't your score be highly skewed?

-also-

if three very very good teams were in the same round on the same team at the same time, wouldnt it also get skewed?

thanks for any input, because the OPR isnt even close to our average point contribution to our allinace that i calculated by hand after watching our regional videos, and our team hopes that teams at ATL won't rely on the OPR greatly for scouting, as it may negatively influence their decisions for alliance parings with our team, as well as many others. once again, thanks!

Re: Offensive Power Rankings for 2008
 

Of course that many things could skew the nubers. However, the law of large numbers still applies: the more and more samples you take, the more the number you're sampling appraoch its true value. So even if one matches is skewed, the average if your ten matches, or maybe more, will still be close to the expect numbers.

I think relying on any one tool too much to make a decision is a bad idea. Look, for example at what NFL teams do before they draft someone: watch game video, look at game statistics, look at the player during workouts, look at iq tests, personal intrviews, and more. Similarly, the best scouring teams in Atlanta will combine several different measurements and inputs to make their lists. I imagine they will go around talking to teams and getting an impression of their strategy, gameplanning, and experience. I bet they will have people recording matches and looking at what each team does, driver skill, performance, etc. I would guess they also watch some teams' recorded matches, especially from eliminations, to see how those teams fair when it's make-it or break-it time. A combination of these different tools is what will probably lead the eventual winning alliance captain to compile its alliance.

Re: Offensive Power Rankings for 2008
 

Off subject a little--Is there a csv with all the teams and their addresses that I can get my hands on. I would love for my Geospatial Tech class to use the opr data and do some geocoding to look at trends.

Re: Offensive Power Rankings for 2008
 

Can someone post CT?

Re: Offensive Power Rankings for 2008
 

I would like to see VCU

Re: Offensive Power Rankings for 2008
 

Here is every single regional. The ordering isn't sorted. The files are just txt files with funny names, just rename the .out extension.

You can get their cities pretty easily off of usfirst.org, but I don't know about addresses.

Re: Offensive Power Rankings for 2008
 

From the "throw a monkey wrench and see what happens dept.":
Has anyone looked to see how much effect surrogate matches have on these rankings? If the number of matches per team determines the matrix size, is the calculation looking to see how many matches a given team actually played? For example, in Philly all teams played 11 matches, but 304 and 381 each played 12: 11 plus one extra surrogate match.

For those not familiar, surrogates are called for to "fill out" the schedule when the number of teams x the number of matches / 6 is not a whole number. Without surrogates there would be some matches with un-filled robot positions. Surrogate match results are not counted in FIRST's ranking scores, and are identified by a "1" next to the team # in the qualifying schedule. This year it is always the third match for a surrogate team.

Re: Offensive Power Rankings for 2008
 

Another thing OPR can't predict is the effect installing any robot upgrades will have on a team's performance at the Championship. Only effective scouting can identify such teams who make any significant changes to their bots in Atlanta which improve their overall scoring output.

Re: Offensive Power Rankings for 2008
 

To build on what others have said about the shortcommings of the OPR, watching the actual matches is a ton better than just looking at the OPR. The OPR attempts to predict how well a team scores per match, and is just decent at it. Relying on only the OPR is like a weatherman predicting the weather simply looking at on the month's average weather, instead of actually looking at the weather patterns, air pressure and all the other stuff weather people look at when making the forcast. By looking at the averages I'll know tommorrow it will be fairly warm, but won't tell me if I should bring a jacket, umbrella or sunglasses. OPR is nice because it gives a rough or general idea about a team very quickly and easily, but to get a good idea about a team, you need to actually watch thier matches.

I would use it only in prescouting where there is no matchs online of the team. In this situation it is better than no information at all.

EDIT: One of the shortcommings is that the OPR attempts to predict something that can be found--the team's contribution to thier alliance--by watching the team's matches. It is nice that is very easy to find, but its not like it is predicting something that we cannot find.

Re: Offensive Power Rankings for 2008
 

I did the same with 330's scouting data for San Diego and LA. We do account for penalties.

For SD, the R value was .8852 and R-squared of .7836
For LA, the R value was .8490 and R-squared of .7200

When I removed penalties from the equation, the SD R value fell to .8620 and the LA R value fell to .8345

Re: Offensive Power Rankings for 2008
 

http://www.thebluealliance.net/cdvid...4_07_teams.csv

Full DB dump of the interesting bits. Enjoy!

Re: Offensive Power Rankings for 2008
 

Teams may interpret "scoring" differently in their scouting systems. If Team A cannot hurdle, but can place the ball on the overpass and Team B cannot place the ball, but can knock it down, together they can hurdle. Individually, their contributions, however, would not indicate that possibility and would reflect only points scored by receiving a bonus at the end of the match or by knocking balls down in hybrid mode.

Re: Offensive Power Rankings for 2008
 

A little off topic, but how did our team drop points, when we havn't played a regional? From 37.472 to 32.54432471???:ahh: :confused: Our last regional was GLR ??????

Re: Offensive Power Rankings for 2008
 

Do you understand the math behind the rankings? Your apparent drop can be explained easily if some of the teams you played with scored more points in later regionals. The algorithm doesn't account for different strengths at different times for the same team. It would tend to overcount an improving team's contribution to earlier matches, and thus undercount its partners' contribution.

Re: Offensive Power Rankings for 2008
 

Same thing happened to us too, that happens if you performed better at a previous regional as opposed to your last one.

Re: Offensive Power Rankings for 2008
 

Someone (don't know if he wants to be revealed) via PM requested the algorithm I've been using, which meant I had to clean my code, which means I'm not as embarrassed to post it.

So here it is:
Required files:
-Reglist.txt - a list of regional data to be processed. One file per line. Note that it will output a file for each file in this list, and that will be the OPR for that regional
-cmpteams.txt - A list of teams that you're interested in (for example, a list of teams going to championships). One team per line.
-the JAMA math library (see attached file). This is from the NIST, it should be ok to redistribute. You can get the actual file here: http://math.nist.gov/tnt/download.html

------------
Licensing: None, do whatever you want with it. Feel free to give me credit or something though (but you don't have to, if it'd cramp your style).

Re: Offensive Power Rankings for 2008
 

http://www.thebluealliance.net/cdvid...08_matches.csv

Match dump including New York City regional. Includes column with event name and event week. Provides column with competition level (to filter out elims, if you want) and match number (probably not useful). Filters out matches with incomplete information.

Re: Offensive Power Rankings for 2008
 

With Greg's new dump, I'm proud to present: my complete OPR rankings. These include every match in the TBA system, including eliminations, broken down as follows: one sheet overall, one sheet for each week, two combined sheets (combining the weekly and overall rankings): one normal, and one with repeats in the top 50 or so color labeled.

Note: the following includes teams' overall performances as well as their weekly ones. If you wish to disregard the overall ones, subtract one from all numbers :P

1114 have the top 3 and 4 out of the top 10 performances overall. 233 have 2 out of the top 10, as do 2056. 330, 987, and 2056 also all have 3 in the top 20, with 39 having 2. Other notable repeats include 217 (3 performances in the 21-42 range), 67 (same), 525 (same), 1124 (2 in 21-41), 40 (same), 1625 (2 in top 50), 103 (same, including the 13th best).

Here are the top 50 performances, be them weekly or overall:
Attached in a zip file is my complete excel spreadsheet.

Enjoy :)

Re: Offensive Power Rankings for 2008
 

Great data... you can definitely see an improvement among teams over the weeks.

Re: Offensive Power Rankings for 2008
 

Here's a theoretical and completely meaningless divisional breakdown for Championships based solely on Bongle's final OPR's and the current 339-team list (sort all teams by OPR, then go (A, C, G, N), (A, C, G, N), etc.

Even if FIRST went with this off the wall sorting system, the addition of the final few teams would skew the arrangement.

Re: Offensive Power Rankings for 2008
 

Is the "contest the score box" online data?

Re: Offensive Power Rankings for 2008
 

By anticipated popular demand, OPRs by division.
Column order is
Team#, # of regionals, last OPR, last regional, best OPR, best regional

Stats that I found interesting:
Archimedes
Curie
Galileo
Newton

Re: Offensive Power Rankings for 2008
 

Can we get an OPR for divisions based on overall performance instead of individual regionals?

Re: Offensive Power Rankings for 2008
 

does the makes us the 14th highest scoring robot in Galileo (based on our last regional)?

Re: Offensive Power Rankings for 2008
 

It means that you have the 14th highest OPR :). That is all it means. OPR correlates strongly with scoring ability, but it also correlates with other things such as teamwork (teams that get in the way of their alliance partners would have lower OPRs) and rule-abiding (see those negative numbers? those teams tended to take penalties). Someone who has scouting data on every single team in FIRST might be able to tell you if you're literally the 14th-highest scoring robot in Galileo. However, since I don't think anyone actually has that much data, this is a nice stand-in. It is certainly something to be proud of.

Overall OPR: Accuracy is directly proportional to a team's consistency over the course of their regionals.

Re: Offensive Power Rankings for 2008
 

How about some statistics on the individual divisions like mean, median, standard deviation, and whatever else might be interesting. I'd like to throw some fuel on the best division debate by seeing how they stack up against each other in OPR.

Re: Offensive Power Rankings for 2008
 

Re: Offensive Power Rankings for 2008
 

This might be immpossible but our team wants to know the rankings for the best hyrid teams in the country..

Re: Offensive Power Rankings for 2008
 

Not possible from these stats, you'd need to consult teams that do lots of scouting.

Re: Offensive Power Rankings for 2008
 

I noticed some people were requesting DPR scores. While the meaning of a DPR number isn't as straightforward as OPR, I think we may be able to improve the OPR calculation by taking it into account. If a team tends to play heavy defense, the teams they play against shouldn't have their OPR reduced when they play below average. Plus I love linear algebra so this gave me an excuse to use it.

<complex math warning>

So here's the equation:

Where (n = total # of teams):
M = n x n matrix with M(ij) = # of times i played with j. M(ii) = # of times i played. (same as M from before)
N = n x n matrix with N(ij) = # of times i played against j. N(ii) = 0.
p = n x 1 column vector of OPRs. p(i) = OPR for team i. (same as p from before)
d = n x 1 column vector of DPRs. d(i) = DPR for team i.
s_t = n x 1 column vector of total scores. s_t(i) = Sum of all of team i's match scores. (same as s from before)
s_o = n x 1 column vector of total opponent scores. s_o(i) = Sum of all of team i's opponents' match scores.

In other words, the first n equations add all the offense played by team i's allies, subtracts all the defense played by team i's opponents, and equates that with team i's total score. The second n equations sums all the offense played by team i's opponents, subtracts all the defense played by team i's allies, and equates it with team i's opponents' total score.

We can rewrite the equation as Ax = y where A = (M -N; N -M), x = (p; d), and y = (s_t; s_o).

In the data set I used, there are 2 isolated sets of teams that played no matches with teams outside their set: the Israeli and non-Israeli teams. We can separate these sets and write an equation for each one, and I think it's easier if we do:

We can solve each equation completely independently, so I'm just going to focus on one equation and call it Ax = y. A has a null space of dimension 1 so it's not invertible. We can increase all the OPRs and DPRs by the same amount without having any effect on the scores, so the null space is the span of x = (1 1 1 ... 1). We can get a unique solution by adding one more equation. I (somewhat arbitrarily) chose the equation by saying: if there was no defense, scores would be 25% higher. In equation form that is:

or
You can tack the last equation onto the end of A like so:
And just ask Matlab to solve Ax = y for you. Or replace a random row in A with ( E 0 ) so A becomes invertible and solve x = A_inv * y.

</complex math warning>

I ran this against the first csv Greg posted and here are the results (top 50, ordered by OPR):

Compare this with Guy's results from the same dataset. The results are fairly similar, but there's definitely some movement in the rankings. Make of it what you will.

Personally, I don't think it tells you a whole lot to know a team's DPR. The two OPRs tell you slightly different things about a team. The old OPR tries to tell you how much a team actually scored each match. The new OPR tries to tell you how much a team could have scored each match if there was no defense. They are both potentially useful numbers.

Finally, knowing both OPR and DPR does allow you to better predict the score of a match. If you define error as:
then both methods are the least squares solution for their respective vector spaces, but method #2 has a lower MSE (mean square error) and ME (mean (abs) error) because it has a bigger vector space (less information loss).

Method #1 MSE = 245.0446, ME = 12.306
Method #2 MSE = 180.8867, ME = 10.514

So it's better at predicting past scores. Is it better at predicting future scores? I guess we'll see.

Re: Offensive Power Rankings for 2008
 

Jay, this is some very inpressive Linear Algebra. This is pretty awesome!

Two thoughts: Would it be possible for you, at some point, to post all DPR rankings from the overall data set? Also, maybe something more interesting for the results, could you try and solve for which correction factor (in the arbitrarily chosen equation) makes for the lowest ME? Maybe that can make it even more vaulble of a tool. I'll also shoot you a PM with another idea I have to make OPR (and probably DPR) even more meaningful.

Re: Offensive Power Rankings for 2008
 

I knew it was possible, finally somebody looked at it.
Thank You!

Re: Offensive Power Rankings for 2008
 

Now that its all over, would anyone like to post OPR based on just matches at nationals (separately for each division). I am interested in observing how teams did at an individual regional compared to nationals.

Re: Offensive Power Rankings for 2008
 

I would like to say -- I love numbers and data. I predicted the scores of all our qualification matches and ( other than the first match that had two of our robots quit ) the scores were within 10% most of the time -- very close !!! We also had the 15th highest OPR in Archimedes -- we ended up the 17th seed -- again very close. Based on the numbers, I said we would go 6-1 -- we were 5-2.

Team 1598

Re: Offensive Power Rankings for 2008
 

I Dont think this has a good idea on what actually counts as reliable data.
We were 15th in Galileo in OPR, however, we dont have a hurdler. All of our points are in auto/laps/assists.
We thought we would go 5-2, but our matches didnt go as planned so we went 3-4.
I like the details of this and i really appreciate it, i have been looking for something this detailed. :)

Re: Offensive Power Rankings for 2008
 

does anyone have OPRs for the Championship Event? Thanks in advance!

Re: Offensive Power Rankings for 2008
 

Can we get the OPR rankings for the IRI. Abra ca iri dadbra......