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-   -   Discrepancy at Chesapeake, Israel, Waterloo? (http://www.chiefdelphi.com/forums/showthread.php?t=76154)

Killraine 24-03-2009 12:22

Discrepancy at Chesapeake, Israel, Waterloo?
 
I looked over the data from all of the regionals of the first 4 weeks after getting back from Chesapeake this weekend. At Chesapeake, there seemed to be an occasional problem where the middle blue alliance station would not establish communication with the robot. I was not surprised to see the data reflected this, with the Red alliance winning 61.5% of the qualification matches. I was surprised to see similar results at both the Israel and Waterloo regionals. Did you guys have a similar problem at your regionals?

Here is the data:
Code:

Regional                    Blue Win % Red Win % Difference
Israel Regional                        37.97%        62.03%        12.03%
Chesapeake Regional                38.46%        61.54%        11.54%
Waterloo Regional                    61.36%        38.64%        11.36%
Pittsburgh Regional                58.06%        41.94%        8.06%
Washington DC Regional                42.11%        57.89%        7.89%
Finger Lakes Regional                57.58%        42.42%        7.58%
NASA VCU Regional                57.14%        42.86%        7.14%
Greater Kansas City Regional  56.94%        43.06%        6.94%
MI - Traverse City                56.58%        43.42%        6.58%
Peachtree Regional                56.34%        43.66%        6.34%
MI - Cass Tech                        56.25%        43.75%        6.25%
Philadelphia Regional                56.25%        43.75%        6.25%
Wisconsin Regional                54.93%        45.07%        4.93%
Midwest Regional                45.07%        54.93%        4.93%
Bayou Regional                        45.61%        54.39%        4.39%
Los Angeles Regional                54.29%        45.71%        4.29%
Oregon Regional                        53.97%        46.03%        3.97%
Boilermaker Regional                53.85%        46.15%        3.85%
Arizona Regional                46.97%        53.03%        3.03%
St. Louis Regional                46.97%        53.03%        3.03%
Silicon Valley Regional                47.62%        52.38%        2.38%
BAE Systems Regional                52.38%        47.62%        2.38%
Oklahoma City Regional                47.76%        52.24%        2.24%
New York City Regional                48.05%        51.95%        1.95%
New Jersey Regional                48.61%        51.39%        1.39%
MI - Detroit                        48.75%        51.25%        1.25%
MI - Kettering University        51.25%        48.75%        1.25%
MI - Lansing                        51.25%        48.75%        1.25%
Dallas Regional                        49.25%        50.75%        0.75%
Buckeye Regional                50.63%        49.37%        0.63%
Boston Regional                        50.00%        50.00%        0.00%
San Diego Regional                50.00%        50.00%        0.00%
Florida Regional                50.00%        50.00%        0.00%

The difference column is merely how far off the results are from a 50/50 split (Obtained by abs(50 - Blue Win %)). You can see it jumps from 8% at Pittsburgh to 11% at Waterloo. Everything up to Pittsburgh seems to go up fairly linearly.

Alex Cormier 24-03-2009 12:27

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Very interesting information. But I am not really liking the "error" name for the difference. How about use the word "difference"? sounds better.

Killraine 24-03-2009 12:31

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Agreed. Error makes it sound like Percent Error, which would be a whole different thing entirely. I edited the post.

Tom Line 24-03-2009 12:42

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Putting your %'s into minitab and doing a simple capability sixpack, the distribution has a P value of .59, which strongly suggests you have a normal distribution.

Looking at the tails of the normal curve, only a couple values fall just outside that range, and you have both a long term and short term capability of well above 2. There is a bimodal distribution, but this sample size of regionals is somewhat limited.

With this limited sample size, my answer currently would be "It's well within expected limits".

Yeah, I know, it doesn't answer your question really. But everything points to normal statistical variation in Team winning percentage.

Jonathan Norris 24-03-2009 12:54

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Waterloo only had 34 qualification matches... So I am not surprised it is a bit off.

Alex Cormier 24-03-2009 12:57

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Quote:

Originally Posted by Jonathan Norris (Post 840453)
Waterloo only had 34 qualification matches... So I am not surprised it is a bit off.

44 Qualification matches.

Killraine 24-03-2009 12:57

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Quote:

Originally Posted by Jonathan Norris (Post 840453)
Waterloo only had 34 qualification matches... So I am not surprised it is a bit off.

Well, that addresses one of them. Does anyone have any details on Israel?


Also, @ the data from minitab: Are you sure its not looking at it on too large of a scale? The data is clearly pretty linear up until the 3% jump.

Tom Line 24-03-2009 13:46

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Any statistician will tell you that statistics never conclude anything - they are merely interpreted to mean something. You can, generally, argue any point you like if you know how to twist them well enough.

However, in this case, I think it's pretty fair to say you've simply found the tails of the curve. Someone's got to have the highest and lowest scores, after all.

vivek16 24-03-2009 15:32

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
I think it's just coincidence, it's not like one alliance color has more at every single regional. The discrepancies happen.



-Vivek

Nuttyman54 24-03-2009 16:04

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Quote:

Originally Posted by vivek16 (Post 840543)
I think it's just coincidence, it's not like one alliance color has more at every single regional. The discrepancies happen.



-Vivek

It's not always coincidence. In the case of Chesapeake, the middle blue station appeared to have chronic problems with dead robots. As we all know, a dead robot is pretty tough to overcome, and is possibly responsible for the discrepancy we've seen at Chesapeake. I don't think it's possible at this point, but I'd like to see the stats on how many matches had a disabled robot at the Blue 2 station, and how many of those matches blue lost.

Seat Ninja 24-03-2009 16:12

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
My team was at Chesapeake. We were mostly on the blue alliance. As you can see below.

rcflyer620 24-03-2009 16:24

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
I was an FTAA at Chesapeake and can tell you the most of the problems with "dead" robots were operator error. The most common was robots going on the field with the cRio un-plugged from the radio. The FTA had made it clear that once the gates were up you could not correct things like that on the field. We even announced it in the pits to no avail.
Unfortunately I also mentor team 2199 who lost a very good chance at being regional champion due to the robot in Blue-2 de-linking after autonomous. The weird thing is that it exhibited the same behavior in the previous match but in Blue 3 lending credence to the argument that it was a robot problem.
One thing I found that was fairly consistent was the flat black ethernet cable provided in the kit was problematic. teams that had swapped it out for real twisted pair ahd almost no problems with communication.

JohnBoucher 24-03-2009 16:30

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Quote:

Originally Posted by rcflyer620 (Post 840563)
The most common was robots going on the field with the cRio un-plugged from the radio. The FTA had made it clear that once the gates were up you could not correct things like that on the field. We even announced it in the pits to no avail.

Really? How many robots were not able to compete because of this?

Kingofl337 24-03-2009 17:17

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Quote:

Originally Posted by rcflyer620 (Post 840563)
I was an FTAA at Chesapeake and can tell you the most of the problems with "dead" robots were operator error. The most common was robots going on the field with the cRio un-plugged from the radio. The FTA had made it clear that once the gates were up you could not correct things like that on the field. We even announced it in the pits to no avail.
Unfortunately I also mentor team 2199 who lost a very good chance at being regional champion due to the robot in Blue-2 de-linking after autonomous. The weird thing is that it exhibited the same behavior in the previous match but in Blue 3 lending credence to the argument that it was a robot problem.
One thing I found that was fairly consistent was the flat black ethernet cable provided in the kit was problematic. teams that had swapped it out for real twisted pair ahd almost no problems with communication.

Yes, it was funny how blue had consistent problems at Chesapeake. So, bad in fact that before the finals two members from team 190 at different times said "I hope you don't end up on the blue alliance". Team 134 ran consistently though qualifications and eliminations never changing their code or robot configuration. We were forced to change to the blue side of the field. On our first finals match, two robot crashed and disabled each other. They disconnected from the field so the FTA claimed it was a power issue. Then on the next match 134 disabled in the middle of the match for no apparent reason and was still connected to the field. All attempts to convince the FTA that field my have been the issue were ignored. In the third match with no changes other than rebooting the robot and swapping driver station loactions with us team 134 ran fine.

Quote:

Really? How many robots were not able to compete because of this?
I know of at least 6 times where the FTA took the time to point out the mistake to the team(s) and told the scoring table to disable the robot.

dk5sm5luigi 24-03-2009 17:48

Re: Discrepancy at Chesapeake, Israel, Waterloo?
 
Quote:

Originally Posted by JohnBoucher (Post 840566)
Really? How many robots were not able to compete because of this?

I would have to say that I saw that happen at least 7 times. The FTA would bring the student out onto the field point out the issue and then disable them before the match started.

On another note do these stats include eliminations? If so then the data won't be accurate because in eliminations the higher seed is in red and in theory more likely to win.


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