The first ROBO-ONE competition, held in February, 2002, drew 29 entries, which was quite a turnout for an infant sport with no established track record. The demonstration phase cutoff for top scorers to qualify for the bouts in the ring was limited to the top 16 robots. Just two years later, for ROBO-ONE 5, there were 82 entries and the cutoff had been raised to include the top 32 robots.
Although the challenges and the scoring have become tougher and tougher with each subsequent competition, participation continues to grow consistently, and the average scores keep going up. The chart above (click on the image for a larger version) is a rough attempt to show how the contest has become more and more difficult as it matures. It's not a true apples to apples comparison because of the scoring changes, but we think it does provide a sense of how things have evolved.
At the ROBO-ONE 10 party the evening of September 16th, some of the officials mentioned that some changes are in the works. One, very welcome change, will be to implement weight classifications. The details haven't been published yet, but it's likely there will be a light or middleweight classification (say under 2 kg) and a heavyweight classification. There was even some joking about a potential 100 kg weight class with humans wearing power suits. That was kind of a bummer to us since we weigh over 100 kg without any clothes on...
There was also mention of implementing regional competitions. Many of the other robot sports here in Japan, like Micromouse and Robot Sumo, already use a regional system, so it's just a matter of time before the shear number of people that want to join in the fun force the ROBO-ONE organization to do something similar. Hopefully they will follow the lead of the other competitions in letting competitors from outside Japan continue to enter the main competition directly.