Offensive Power Rankings for 2008
 

Inspired by a post by sw293 in one of my long-past stats threads from 2006, I re-implemented his/her Offensive Power Rankings algorithm. Essentially, it tries to determine approximately how much each team, on average, contributed to their alliance.

You can see the math behind it detailed here: http://www.chiefdelphi.com/forums/sh...0&postcount=19.

In essence, it looks at a team's accumulated score over the course of a weekend as a sum of the offensive power ratings of all the other teams, multiplied by the number of times that team was paired with each team.

Example: 1565's first match at GTR was with 2198 and 1870, and they played 8 matches total. The '...' would be all their other alliance partners through qualifying, multiplied each time by how many times they were allied with them.

TotalScore(1565) = OPR(1565)*8 + OPR(2198)*1 + OPR(1870)*1 + ...

Once you arrange the scores of all the teams from a regional in this way, then you end up with N equations (one big sum of scores per team) and N unknowns (the offensive power ratings). This can be solved to find out the OPRs.

Without further ado, here they are for GTR. I'll be doing other regionals in the very near future.

Re: Offensive Power Rankings for 2008
 

These power rankings were a great help in 2006. (very accurate and very predictive) Of course they did not predict the exact outcome of matches, but it certainly let a team know what they were up against and who they were partnered with. It was a big part of our Championship scouting routine in 2006.

Thanks for offering to do this!

Re: Offensive Power Rankings for 2008
 

The penalties are such a huge factor this year, unless you find a way to account for them, this formula won't accurately reflect a teams offensive ability.

Re: Offensive Power Rankings for 2008
 

Exactly correct. These shouldn't be used as the be-all end-all of scouting, but perhaps as pointers to find gems in the rough. There are many things that can happen in this game (and in other years) that aren't encapsulated in a simple number.

Re: Offensive Power Rankings for 2008
 

This is actually better then a team's offensive ability. It shows a teams point contribution. If a team is consistently penalized, they will have a lower OPR then a team that scores the same points per match but does so without penalties. You would obviously want the latter on your alliance.

Another interesting thing is that a team that constantly gets in the way of it's alliance parters would have a lower OPR then one that scores the same number of points but allows it's alliance partners to live to their full potential.

Re: Offensive Power Rankings for 2008
 

are thier going to be ones for every regional? or would that be an endeavour of the individual teams to do?

Re: Offensive Power Rankings for 2008
 

Just finished the complete list. This includes every single 2nd-week and later regional. The first-week regionals have slightly different formatting for match results, and I couldn't include them easily. At least based on this analysis, we finally have an answer for the question: "Is anyone CLOSE to 1114?". The answer: no.

The top 50:
See the attachment for the rest.

Re: Offensive Power Rankings for 2008
 

I don't see entries for any teams I remember from Microsoft-Seattle Regional (Week 4). :confused:

Re: Offensive Power Rankings for 2008
 

A team can have a great scoring record and have few penalties but can still have their rating ruined by being on alliances that have scored penalties.

If you can't factor out alliance penalties then there is way too much "luck of the draw" possible in this chart.

Re: Offensive Power Rankings for 2008
 

It had funny formatting, but upon thinking about it some more, I don't think it should badly affect my program's ability to read it. I'll put it in and re-do them.

In fact, I can think of a way I should be able to get the week 1 regionals working as well.

Check this thread again in 10 minutes, I should have an updated one up.

Re: Offensive Power Rankings for 2008
 

If you let me know a precise format you want, I can give you a huge CSV dump into the formatting you want from The Blue Alliance's database.

Re: Offensive Power Rankings for 2008
 

I would also like to see standings of all teams ranked based on their record at the attended official events (Win-Loss-Tie). :)

Re: Offensive Power Rankings for 2008
 

"Red1 <tab> Red2 <tab> red3 <tab> blue1 <tab> blue2 <tab> blue3 <tab> redscore <tab> bluescore <line feed or carriage return or end of line or whatever>" is all I need. That'd be great. CSV is good too, I'm not particular about the delimiter.

So including week 1, the top 50 now looks like:

Re: Offensive Power Rankings for 2008
 

The CSV is too big to attach. Find it here: http://www.thebluealliance.net/cdvid...30_matches.csv

Let me know if that works for you :)

Re: Offensive Power Rankings for 2008
 

Okay I somewhat understand how this is all calculated but I am guessing that somebody has already made an excel file to calculate all this? I tried to download one from '06 but the link was broken so can somebody please upload a new one? Thanks.

Re: Offensive Power Rankings for 2008
 

Could you help me make sure I understand the linear algebra involved?

I understand that p is what we're looking to find, or the average number of points a team contributes per match. s and M we can calculate from the results coming from each regional. Since Mp = s, we can conclude that p = (M-1)s (where M-1 denotes M inverse). It seems to me from thinking about it that M is symmetric, and as such M = M-1. Is that actually the case?

I'll probably try to write a program to take a csv dump and spit out rankings if I understand the math.

Re: Offensive Power Rankings for 2008
 

M is indeed symmetric. M[i][j] indicates how many matches team i played with team j. Therefore, it makes sense that M[i][j] = M[j][i].

I don't think the inverse of a symmetric matrix is necessarily symmetric. The transpose of a symmetric matrix M would be equal to its non-transpose, but I don't think that carries for symmetry. To prove that M^-1 is not necessarily equal to M for a symmetric matrix, just think of the symmetric matrix 2I, where I is the identity matrix.

If (M)^-1 = (M) for symmetric matrices like you are proposing, and we know MM^-1 = I for any matrix and its inverse, then (2I)(2I) must equal I, but this is not the case.

I didn't have to write the matrix solver myself, I used a library I found online. If there are any tricks it used, I'm not aware of them.

Re: Offensive Power Rankings for 2008
 

You're right. For some reason, I was thinking of the transpose rather than the inverse. I'll see how I handle the inversion of the matrix when I get there. In the meantime, I'm working through the easy stuff: reading the csv and making and populating s and M.

Re: Offensive Power Rankings for 2008
 

M is symmetric, but that doesn't mean M = M inverse.

Symmetry means that M = M transpose (flipped along the identity axis), which is different than M inverse.

It's easy to confuse the two (I remember doing that plenty of times, thank Ms. Martin).

Here's an example where M = M inverse, and you quickly see that M is definitely not symmetric:

Re: Offensive Power Rankings for 2008
 

Just an FYI...all of the match data is NOT included from the Peachtree regional. The scoring system failed so all of the elimination matches and many of the qualifying matches from Saturday are not included. As an example...team 343 finished 12-4 at that regional. We are still shown as 5-3 on the Blue Alliance. That means there are eight matches not accounted for on us alone. That would/could be the same for many of the other teams who attended Peachtree.

Is there anybody that has that manual data? Can it be manually entered into the Blue Alliance?

Thanks,
Mike Carron
Team 343

Re: Offensive Power Rankings for 2008
 

See here: http://www.chiefdelphi.com/media/papers/2102

Re: Offensive Power Rankings for 2008
 

but...was anyone planning on putting this manuel score on tba... b/c i have no way to do it...

Re: Offensive Power Rankings for 2008
 

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?

Re: Offensive Power Rankings for 2008
 

Okay, I have created a basic program to make the n X n matrix as defined in the post that sort of explains the rankings but what do I do from there? I am only in trig and we have definitely not learned that stuff with matrices. Can somebody give me an example of "M(k1)p(1)+M(k2)p(2)+...+M(kn)p(n) should equal s(k)" or clarify that please? Thanks!

Re: Offensive Power Rankings for 2008
 

We were hevily defended all through GLR hurdling only 2-3 times a match where we usualy hurdle 4-6 times and at Detroit we were broken 3 of the matches, but we are still high on the list:ahh: . That shouldn't effect it much.

Re: Offensive Power Rankings for 2008
 

From there you need to invert M and multiply it by s. The are libraries doing the first all over the internet - however, I do not know the algorithm they use. I know how to do it manually, but that would take way too much time for anything this scale.

Then you need to multiply M inverse by s. What you're looking to get out is another column vector, or list of numbers, similar to the one you have in s, although with different numbers. To do that, simply multiply each element in a column of M inverse (with a fixed row) by each element in the corresponding row in s (which has only one column). For example, to find the 10th element of p, or the average number of points contributed by the team in the 10th row, add up M(10,1)*s(1) + M(10,2)*s(2) + M(10,3)*s(3) + ...

Doing that for each row in M will get you p, the vector you're looking for.

If this didn't make much sense, look at http://mathdemos.gcsu.edu/mathdemos/matvec/matvec.html or http://en.wikipedia.org/wiki/Matrix_multiplication

Re: Offensive Power Rankings for 2008
 

I added Peachtree missing matches to the database. I'll do another database dump after the NYC regional is finished. Thanks for pointing me to the data!

Re: Offensive Power Rankings for 2008
 

Looks like the system is working well, but I think if we add a little to it it would work much better.

Right now it is set up to calculate the average points contributed to an alliance by one team. This method does not take care of the defence.

you guys who did the calculations, can you add defence to it as well.

so example:
Red Score = RedA_O + RedB_O + RedC_O - BlueA_D - BlueB_D - BlueC_D
then solve for Team_O which is the average points added to their alliance, and Team_D which is the average points one team take away from their Opponent's alliance.

Re: Offensive Power Rankings for 2008
 

Just a few questions left but the post above helped a bunch. Do i want M inverse or transverse? Also, do I want it to equal s and multiply by p or the other way around? Lastly, M(10,1)*s(1) + M(10,2)*s(2) + M(10,3)*s(3) Means to take whatever value is in the matrix at (10,1) and multiple by s and by 1 right? thanks!

Re: Offensive Power Rankings for 2008
 

Hey Kyler:
Do you want me to send a slide rule with Nathan tomorrow to help you out?
Nesher

Re: Offensive Power Rankings for 2008
 

Bongle-

Are you going to do recreate the rankings after all the regionals are done and before the finals in Atlanta?

Re: Offensive Power Rankings for 2008
 

Lol I think I can have the computer do most of the math for me. I just have to understand it... thats my hope at least.

Re: Offensive Power Rankings for 2008
 

I could re-do them once this week's regionals are complete, that's not a problem.

I'll do an Atlanta-only one after ATL too if there is demand.

Re: Offensive Power Rankings for 2008
 

I am not a programmer, but here is an interesting challenge for someone with some time on their hands. Once Atlanta divisions are posted, use the OPR to pick the winning alliance assuming that the rankings and draft follow the OPR (alliances would be 1,2,24-3,4,23-5,6,22......). Obviously the OPR will pick 1114 and some other powerful hurdler as the winners, but I am curious how closely it may actually predict things.

Re: Offensive Power Rankings for 2008
 

To go even further:
Use the match scheduling algorithm to generate a schedule, then simulate each division's games, assuming that the alliance with the higher OPR always wins. Now you've got more accurate simulated rankings, because you may even have a weaker team get into the top 8 due to luck with the scheduling. However, you'd have issues because in the real world there'll be draft rejections which you can't plan for.

Then do the division playoffs and Einstein simulation. I may do that after my first exam when I have a long time off.

Re: Offensive Power Rankings for 2008
 

Hate to ask for more, but here goes:
I noticed our OPR drop dramatically when week 1 was added in (we had a lot of technical difficulties). Is anyone planning on doing an OPR ranking only using a teams last regional? This may more acurately show how the teams will perform at Atlanta....

Re: Offensive Power Rankings for 2008
 

That's a really good point. I know when I'll prescout for my team, I'll focus on the team's last regional because it usually the best predictor to see how a team will preform. Maybe you can weigh the different regionals (such as if a team attends 2 regionals, the first regional may be 30% while the second will be 70% of thier total score).

Re: Offensive Power Rankings for 2008
 

Good point! We are definitely a much better machine now then we were at Chesapeake. Our drivers also have more confidence in the machine.

Re: Offensive Power Rankings for 2008
 

Well, just something interesting I have found. Its to be expected and nothing major but it dies go to show being very percise (adding 4 decimal points) Can change things quite a bit in ranking the teams. To test my own Power Ranking program I ran the GTR results and found my results were different that bongles by up to a point (might not seem like much but once you get to the lower power rankings it is 10 % +) and it changes orders a lot. Here's what i found.



Nevermind, I entered one score wrong. My results are the exact same but with 4 excta decimal points.



I only included a few differences because the teams start to change then and I was too lazy to sort that all out. Also, a big THANKYOU! to everyone that helped me understand this stuff.

Re: Offensive Power Rankings for 2008
 

Kyler,
Will you post your program code for review? I think that your are on to something by adding precision to your calculation.:)

Re: Offensive Power Rankings for 2008
 

Wee, I managed to break java :P

My inversion algorithm for the 1465x1465 or so matrix runs out of heap space. I'm currently working on an alternative way to get p. Right now, I'm going from Mp = s to p = Minverses. I might try to create an augmented matrix and rref it to get the solution. Any other ideas?

EDIT: Nevermind, I just solved the equation Mp = s.

Greg, I now have the OPR's generated from the entire csv dump you generated. Is there any way you could generate other csv dumps to analyze? By regional, by week, over the last three weeks, etc., all sounds like interesting sets of data to analyze.

Re: Offensive Power Rankings for 2008
 

I have the rankings generated from Greg Marra's csv dump of the TBA database.

Top 50:
The entire spreadsheet is attached. I'm working with Greg Marra on getting some more specific data sets and analyzing them, and after I do that, I'll post the results. Any specific requests?

Re: Offensive Power Rankings for 2008
 

for some reason, i dont think that ours is right... b/c we have had three hurdles or more in 75% of our matches and it shows that we score about 26 points per match, which w/ three hurdles (including lines) we should be just a little under 30... but of course i dont know what went into the compiling:cool:

Re: Offensive Power Rankings for 2008
 

Is this data supposed to be your average score or your potential average? What exactly is your number supposed to mean?

Re: Offensive Power Rankings for 2008
 

It is an estimate of how many points your teams contributes per match. Note that it isn't simply your total score / 3, but by using the magic of linear algebra, you can solve for something a bit more accurate. It can help weed out robots that simply had good partners, and should be able to discern robots who many not have placed well but still contributed each round.

If you took a substantial number of penalties (1 every couple matches), that'd result in your offensive rating going down. This is because in addition to adding to an alliance score by hurdling, you'd be subtracting from it due to penalties. It's not a perfect number because we don't have an infinite number of matches to base it off of, but it seems to correlate nicely with observed robot performance.

Re: Offensive Power Rankings for 2008
 

ssCurious...what data or calculation changes explain the reduction of up to almost 3 points from the previous ranking for some teams listed? If the previous calculations were based on results through the 5th week regionals and there has been no additional results/data, what explains the changes observed for this list?

Re: Offensive Power Rankings for 2008
 

Since Sumadin and I went off of different data sets (him from TBA CSV's, me from usfirst.org) and used different algorithms, some perturbation is expected. There could've been a few missed matches in one of our data sets. This is my best guess for why there is a difference between our outputs.

Also, different methods of inverting the matrix could cause somewhat substantial differences in the floating-point input.

I haven't had the time to update my program to use TBA's CSV dump, so we won't be able to compare until probably tuesday when my classes end.

Re: Offensive Power Rankings for 2008
 

The Blue Alliance data includes elimination matches, which I would assume accounts for the majority of the difference. I think the result is probably better with only the qualifying matches.

The Blue Alliance data also gives scores of -1 for the missing peachtree matches (which are now in TBA database, so they would be included for the next data dump).

I've attached just the GTR qualifying matches (which I pulled from TBA's big dump) so that it is possible for sumadin to check his results against Bongle and Kyler's.

Re: Offensive Power Rankings for 2008
 

Our actual average score was 23.11 for our two regionals including penalties. You have us at 13.585. That's a huge difference.

I also see a couple of teams on your list that I know who's scores are way to high.

As I have said from the beginning the algorithm just won't work unless the penalties are somehow added in. They are just to important to this years game.

Re: Offensive Power Rankings for 2008
 

I don't think you're following what Bongle and others are doing. They're not calculating simple averages. They're using basic linear algebra to calculate the average expected value of pure points contributed to the alliance by a single team. This is used by setting up a system of equations which sum to the amount points scored at the regional. Since penalties are already removed from the final scores of all matches, this method takes them into account. The penalties are already "added in". This method is a far more accurate predictor of a team's contribution then just looking at a simple mean. Naturally you team's result is going to be lower than your average score, because this statistic is just looking at your team's contribution.

Re: Offensive Power Rankings for 2008
 

Here are my GTR numbers. If they look wrong, and someone java-literate feels like checking my algorithm, I'd love to send it to you.

Re: Offensive Power Rankings for 2008
 

Guy,

You might want to look into using Maple or Matlab. They're design for these types of computation, plus I'm sure you'll find plenty of other uses for them. I've found them to be indispensable tools.

Re: Offensive Power Rankings for 2008
 

They are exactly the same as Bongle's to 4 decimal places. Good job!

Re: Offensive Power Rankings for 2008
 

I was running the TBA data set. It seems that my numbers for GTR match Bongle's so the computation seems to be correct. Is it possible he isn't using elimination round scores? Because that might cause a drop.

Re: Offensive Power Rankings for 2008
 

Yeah, I didn't use elimination rounds because I feel they kind of distort the results. Playing matches with random robots against random opponents, I think you'll get a better feel for a team's contribution than when they are playing with a self-selected team against the creme de la creme at the regional. Although I guess if you want to take these numbers as scouting pointers rather than for entertainment value, a team's elimination performance is important.

For instance, take 1114 at GTR in the eliminators: they were playing with a team that they founded and they had won 3 regionals with. That team of robots will probably work together much better than a random team in qualifications, and so the scores will be different.

Another thing is that during eliminations, robots steadily get worn down: mechanisms break that can't get repaired in time, batteries slowly get discharged, motors overheat, and so you get things other than the team's competitiveness affecting the scoring level.

Plus, at a shallower regional like at waterloo, you'll end up with things like 1114/2056 against 3 teams who can't even hurdle, and the scores will be ludicrously high.

Said much better than I ever could.

Re: Offensive Power Rankings for 2008
 

I understand that, what I am saying is that their calculation of my teams expected contribution is no where near my teams actual contribution including subtracting the penalties.

Also I see several teams who's expected contribution is way to high from my experience of their performance this year.

If you guys want this tool to be useful you need to figure out why.

It's just my theory that it can't property calculate the impact of penalties, if you think this theory is wrong then you need to figure out what is causing the figure to be so different than the actual results.

Re: Offensive Power Rankings for 2008
 

Mathematically, this method is 100% sound. Whether you see any value in the mathematical model is for you to determine. I'd like to know your mathematical reasoning for why this method doesn't take penalties into account. If all you're relying on is selected cases of anecdotal evidence, your theory holds very little weight with me.

By no means am I suggesting that this model is perfect. From the numbers that Team 1114 has run, there are some definite anomalies. That being said, for the most part this model seems to agree with the specific match data we've collected at three events we attended.

Like with most statistics, the value is all in how you interpret them. If you don't think they're accurate, ignore them.

Re: Offensive Power Rankings for 2008
 

Just to emphasize the quality of OPR as a predictor of who will be playing on Saturday afternoon. Keep in mind, this was a 66 team regional, and predicting 24 robots out of the field is no small feat.

Here's the top 24 OPR from the GTR, and whether they were picked in the elims:

20/24 is a ridiculously decent hit rate. It should be higher since you couldn't expect this algorithm to predict that 703 would graciously withdraw.

Expect all good scouting teams to be using these stats in the very near future.

Re: Offensive Power Rankings for 2008
 

I am not a mathematician, I saw numbers that were wrong (not a little wrong, WILDLY wrong) and I posed a theory based on my feeling not on any math.

We are not competing in Atlanta so I have no need for this data, all I am saying some of what I see in spreadsheet is very wrong.

You can ignore it, I don't care.


Edit: I'll still buy you a doughnut in Atlanta.

Re: Offensive Power Rankings for 2008
 

All I understand is 1114 has an impressive score...
Which seems to fit their impressive robot.

Nice work... this will make a excellent tool to help newbies .

Re: Offensive Power Rankings for 2008
 

Sumadin
Your latest OPR must have an error (86 1.478877681). All the previous OPR data runs had Team 86 with an OPR between 8.8 and 9.2 points. Our actual average for the Florida Regional was 11.5 points. The difference of over 2 points can be explained by the fact that our 1st match included two no show partners. However, I can not figure out the 10 point difference in your post today

Re: Offensive Power Rankings for 2008
 

Note that 1676, #1 pick for Alliance #7, was ranked in the high 40's based on win/loss record. Similarly, we were ranked in the 50s in NJ, but were picked for the 8th alliance.

Why? What team in their right mind would choose a team with a 3-5-0 record?

Teams that understand the math behind the scouting, that's who.

Don

Re: Offensive Power Rankings for 2008
 

Sumadin's included eliminations. It is possible that your alliance partners during eliminations were both scoring below their qualifying performance (which would make sense, given the increased quality of the opposition), and the algorithm 'attributed' that to you. This is why I didn't include eliminations in the ones I ran, they're a whole different beast. It probably isn't a bug in his code, because we both independently developed our own code and our results match, so unless the math foundations we're basing this on are shaky, it's probably an effect of using the finals data.

In other news:
This intrigued me, so I did it for a few more:
GLR: 20/24
Florida: 19/24
VCU: 17/24

So it is a somewhat accurate predictor, but it doesn't take into account that a team's 3rd pick is likely to be a lower-scoring lap bot because of the game only having 2 trackballs. Picking strictly by OPR is a fast way to get eliminated, because you'd probably end up with 3 delicate, relatively slow hurdlers fighting over 2 trackballs, rather than a more-ideal combination of 1 robust lapper/defender and 2 hurdlers.

Re: Offensive Power Rankings for 2008
 

Can I see the OPR from GLR?

Re: Offensive Power Rankings for 2008
 

(based on qualifying matches only)

Re: Offensive Power Rankings for 2008
 

do you have one for each regional? b/c if you do, i would like to see palmetto... b/c i never got to see any statistics:(

Re: Offensive Power Rankings for 2008
 

I have to generate them manually per-regional, so for now I'm going to keep it on a request basis. Enjoy!

Palmetto

Re: Offensive Power Rankings for 2008
 

So all i gotta do is say

"Can i see the opr's for the wisconsin regional?"

and they will magically appear a few posts down from this one?

Re: Offensive Power Rankings for 2008
 

thats how mine worked:D

Re: Offensive Power Rankings for 2008
 

Ha, I was just gonna ask for the same. I'm interested to see how this compares to the statistics of points scored per match that we scouted.

Re: Offensive Power Rankings for 2008
 

well we'll see if this magic works...


ABRAWisconsinRegionalKADABRA!!!

Re: Offensive Power Rankings for 2008
 

Lol, subtle

Wisconsin Regional

Re: Offensive Power Rankings for 2008
 

Again, not a programmer, but I have an interesting idea for writing a DPR (Defensive Power Rating) algorithm. Take your OPR values, apply them to the matches. The delta between the expected score and the actual score would be the raw value for a DPR score. Use your OPR techniques to then factor out the DPR each team might provide.

One thought on why your average score is much higher than your OPR is that a decent hurdler may actually slow down the scoring of an exceptional hurdler. Take for instance an 1114. I know they have done 7 hurdles and may even have done 8 in a match. The match where they did 8, probably would not occur with 2 other decent hurdlers as they may hurdle also and thus accidentally slow down an 1114.

Thanks for posting your results.

Re: Offensive Power Rankings for 2008
 

oh thank you it seems like there really is magic in this world

*looks up with his fingers interlaced in a weird disney like pose*

Re: Offensive Power Rankings for 2008
 

Bongle, not that you need additional validation but your numbers match up exactly with the numbers that our guys have calculated.

This information in the hands of teams that know how to use it will be very dangerous :) ...

I know that I plan to have up to date information in Atlanta for our division.

Although there is no replacement for watching matches and see teams improve through out the weekend. I will have to keep my 'black magic' going and pull more 503s out of my hat, or they just might replace me with a OPR scoring database.

Re: Offensive Power Rankings for 2008
 

Although I love these numbers as and overall indicator of offensive contribution among many teams many matches, they are no substitution for scouting at your event and recording "actual" contributions. These numbers are great to scout with going into Championship. However, if you only use the numbers from 5 qualification matches (per team) to evaluate teams and generate your list on Friday night, there is something wrong with your methods. (Shawn, I know you were not thinking of these number as replacements for all other scouting)

My explanation for why the data is seams like it is skewed towards the extremes is team coordination, track speed, and defense. When very good teams get to together, this is a different game (you can see it in the elims). They are able to coordinate their strategy better (particularly hybrid mode). Ex. If a partner's hybrid routine bumps knocks off their higher-scoring partner's hybrid, that can easily cost the alliance 20+ points (which would reflect very badly on the the OPR of lower scoring bot). When good scoring machines are together (particularly when they are on both alliances) the track moves a lot quicker and there are very few traffic jams, so everyone scores more. If there is defense being played, it will likely only slow down the higher scoring machine, so the impact of the scoring capabilities of the partners is increased. These reasons should also explain some of the differences between regionals. Of coarse there is always the random variable of luck, but we will assume that is zero mean:D Well thats my $0.02

Re: Offensive Power Rankings for 2008
 

personally i like these numbers. No its not a substitute for scouting but it atleast lets you know who you may want to pay closer attention to. I also like the new list as 1629 moved up to 40th!!

Re: Offensive Power Rankings for 2008
 

I'm not sure I saw this yet, but thought it would be interesting to cross reference the OPR with the CMP teams that are currently on the list... Here's the top 50 CMP OPRs...

Re: Offensive Power Rankings for 2008
 

Can you do the full CMP list as of now?

Re: Offensive Power Rankings for 2008
 

Doug, 191 was a member of the winning alliance at FLR.

Re: Offensive Power Rankings for 2008
 

Bongle
Your assumption is correct that Team 86 was a lapbot/defender. Our alliance won the elimination 6-0 at the Florida Regional with scores the ranged from 60 to 116 for 77 point average. I earlier tried to include the use the eliminations for the Florida Regional like Sumadin and the results were very skewed. So the matrices have a problem when the elimination match data is used to solve the matrix. I am still puzzled as to why the eliminations skew the OPR results so drastically (8,8 OPR no elims versus 1.47 OPR with elim)

Re: Offensive Power Rankings for 2008
 

233 and 1251's OPR add to 81, so overall the alliance underperformed* based on the qualifying OPRs. Therefore all three robot's OPRs should go down a little. Those 6 elim matches were 20% of the matches that 233 and 1251 played this year (they went to other regionals too). It was over 40% of 86's matches this year, so 86 would see more of an effect.

Also 233 performed much better at Hawaii then they did in Florida. Since there is only one OPR for the year, it looks like Pink underperformed at Hawaii and overperformed at Florida. I think that 86's OPR would change less when adding in the elims if you were looking at the Florida data only.

*by underperformed, I mean as far as OPR is concerned. It's likely that more defense was played in the finals and was the cause.

Re: Offensive Power Rankings for 2008
 

Joe,
The Hawaii data for 233 is 53.16 pts versus 35.63 pts at the Florida regional. This 18 point change in OPR probably reflects on the fact that the current matrix mathematics would need a strength of schedule adjustment when comparing 40+ regionals. Has 233 improved its offence by 150% in Hawaii or is the competition 66% as strong? In contrast 1251's OPR varied by only 1 point between Florida and South Carolina.:D

Re: Offensive Power Rankings for 2008
 

can you post the boston regional OPR?

Re: Offensive Power Rankings for 2008
 

I'd think that the change in our scoring average could be due to a few things:
At Florida, there were 3 qualifying matches where our tower was 100% inoperable and 2 elimination matches where our top roller did not work, leading to below-average scores there. Also, our autonomous scored about twice as many points in Hawaii than it did in Florida.

Re: Offensive Power Rankings for 2008
 

There may be a few more to add in this next week as NYC finishes up.

I simply took the TBA list and crossed it with the OPR list. TBA must not have 191 as winning. But I'll update the posted list.

Re: Offensive Power Rankings for 2008
 

Yea, this was mostly due to the fact that at palmetto our partners weren't as good. Also having a bull's eye on the robot doesn't help... :D

I love this power rankings, judging by the teams at the top and what I have seen at competitions. It is a good indication of what teams are scoring. This would be a good tool to do some scouting on what teams to watch for on Thursday at the Championship. (Once divisions come out.)

Re: Offensive Power Rankings for 2008
 

can we please get a top 50 with the elimination rounds. i think it would be intresting to see these stats

Re: Offensive Power Rankings for 2008
 

Guy's values in the following post include eliminations:

http://www.chiefdelphi.com/forums/sh...7&postcount=42

Re: Offensive Power Rankings for 2008
 

yeah... one of our mentors actually put a bullseye on our robot:D it was quite entertaining to me!

Re: Offensive Power Rankings for 2008
 

So... I'm really curious to see the OPRs for the Colorado Regional...

Re: Offensive Power Rankings for 2008
 

If I recall correctly, there was a match at Palmetto in which a cretain orange robot made a bee line to ours once their elevator broke.:D Too bad one of us didn't end up winning it. Good luck in ATL.

Re: Offensive Power Rankings for 2008
 

yes, i think i remember that too josh;)

Re: Offensive Power Rankings for 2008
 

ABRAcoloradoregionalKADABRA! lol i'm curious too:D

Re: Offensive Power Rankings for 2008
 

SVR and Davis please?

Re: Offensive Power Rankings for 2008
 

Sorry, I've been out with friends and doing homework for the last couple days.

Colorado
SVR
Davis

Re: Offensive Power Rankings for 2008
 

Can we expect a CMP OPR by sometime tonight or tomorrow?

Re: Offensive Power Rankings for 2008
 

probably more like wednesday or thursday... horray for fill-ins!:p

Re: Offensive Power Rankings for 2008
 

I'll post a championship OPR by division once the division lists come out, so probably sometime this or next week.

Re: Offensive Power Rankings for 2008
 

GRR!!! Must have scouting information!