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:
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.
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.
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.
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.
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.
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.
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.
That is not accurate, because the new scoring software cannot swap alliances. We were denied our request to stay on red alliance despite being the higher seed.
It is close enough. The only time it isn’t true is if an alliance beats a higher seed alliance. Either way most of the time in the eliminations the red alliance has a higher chance of winning which then would make these stats inaccurate if eliminations are included.
Despite dead blue robots, This trend seems to pop up every once in a while. “The Red alliance wins more, bla bla bla, not fair, bla”.
I saw an article a while back saying in a lot of 1v1 Olympic sports, red was more likely to win, but by the same small amount shown here.
I chalk it up to random chance, as at every regional I’ve seen the amount of No-shows is far more than the amount of dead robots, so I can’t imagine the dead robots making a huge difference overall.
