Run Amok Combat Robotics What Weapons Win -- Active versus Passive -- 2016 updatePrivacy Policy
In 2006 I ran a statistical analysis of combat robot tournaments for the prior year to compare the performance of robots with kinetic energy spinning weapons ('spinners') to other 'active' weapons, and to robots with entirely passive weaponry. The 2006 study found that on average robots with kinetic energy spinning weapons had a lower percentage of match wins and lower rankings than robots without spinning weapons, and that active weapons in general were less successful in these measures than were robots with non-active weapons.
There have been significant changes to spinner weapons in the last ten years: brushless weapon motors, exotic single-tooth disks and drums, and much higher kinetic energy storage. I decided to repeat my analysis with current data to see what effect these changes have had on actual match performance.
Method
The 2006 study used tournament records for the 12-pound 'hobbyweight' and 3-pound 'beetleweight' class robots because they were popular weight classes and were commonly featured at tournaments. The beetleweight class has prospered and has 258 active and ranked robots listed at BotRank as of June, 2016. The hobbyweight class, however, has declined both in popularity and weapon diversity. The 30-pound 'featherweight' class has grown to exceed the hobbyweight class in the number of matches, the number of competitors, and the styles of weaponry represented. For these reasons I elected to replace the hobbyweight class with the featherweight class for the current study.
The number of currently active and ranked beetleweight robots (258) is an uncomfortably large group for this project. The previous study examined the 40 beetleweight robots that had competed at any of twenty tournaments held in 2005. The single largest recent beetleweight tournament at the time of this study (June, 2016) was the Motorama event held in February, 2016. A field of 38 beetleweight robots participated in that event, and I selected those competitors as my beetleweight sample for analysis.
The number of currently active and ranked featherweight robots (26) is a workable number for the analysis and compares well to the 24 hobbyweight robots used in the 2006 study. I used the entire group of active featherweight robots for my analysis.
For both weight classes I collected each robot's lifetime tournament record from Botrank.com on June 15th, 2016 and matched that data to weapon information from Builder's Database. Video from recent tournaments was used to supplement the weapon data where the database entries were unclear.
For purposes of this study, weapon categories are defined as follows:
1) A 'spinner' is a fully rotating kinetic energy weapon intended to damage the opponent by impact.
2) An 'active' weapon has a power source separate from the drivetrain and requires its own controlling radio signal.
Note that not everything that spins is a spinner, and not all spinners are active weapons:
A small rotating saw on an arm that decends to cut into an opponent is 'active' but is not an impact 'spinner'.
A dedicated 'thwackbot' that spins only by drivetrain power is not 'active' but is an impact 'spinner'.
The data for the two weight classes is summarized in the tables below:
Beetleweights: 2016 Motorama Tournament
Name
Win
Loss
Rank
Spinner
Active
Airhead
1
1
77
1
1
Ami
0
2
213
1
1
Barrel Roll
4
4
251
1
1
BEST KOREA
10
7
35
1
1
Crazy Monkey
2
0
43
0
0
Deathcap
6
3
36
1
1
Emmii
0
2
191
1
1
Full Metal Breakfast
0
2
181
0
1
Ghoti
2
2
94
1
1
Hard Drive 2.0
2
2
75
0
0
Margin of Safety
15
1
1
1
1
Misti
4
1
28
1
1
Mombot
2
2
103
0
0
Mowbot
3
9
235
1
1
Nocturne
2
6
248
1
1
Project Darkness
13
4
8
1
1
Quicksand
3
4
112
0
0
Ravage
0
1
164
1
1
Revenge of Dr. Super Brain
38
17
40
0
1
Sandi
0
2
182
1
1
Scrambles the Death Dealer
7
16
246
1
1
Shelli
0
2
214
1
1
Silent Spring
23
11
4
1
1
Sloppy Seconds
2
3
113
1
1
Son of Thunder
4
2
46
0
0
Speed Wedge 3
17
4
5
0
0
Super Veloce
6
1
18
0
0
The Collective
10
10
175
0
0
Thumbnail Not Available
1
2
115
1
1
Thunder Child
11
14
76
0
0
Trilobite
29
18
16
0
0
Wedge of Allegiance
4
2
38
0
0
Wedge of Destruction v3
1
2
176
0
1
All ranked Featherweights from BotRank (6/15/2016)
Name
Wins
Losses
Rank
Spinner
Active
Also Riptoff
3
2
6
1
1
Big Black Richard
0
2
21
1
1
Big Ripto
4
2
4
1
1
Candy Paint and Gold Teeth
1
3
18
1
1
Cathii
1
4
25
1
1
Delta
0
1
17
1
1
Derp3
0
2
22
0
0
DrumThing Else
3
7
26
1
1
General Lee
1
4
23
1
1
Glasgow Kiss
4
3
5
1
1
Gloomy
12
12
13
0
1
Gracious Pipe-fessionalism
3
4
20
1
0
Hyper Active
2
4
10
1
1
megatRON
7
5
3
0
1
Miss Fortune
1
3
19
1
1
Omega
1
2
15
0
1
PMTH
3
7
24
1
1
Ruby Rose
1
2
14
0
0
S.S. Impact
2
2
9
1
1
Spur
1
2
11
1
1
Styx
5
0
2
0
0
The Magnificent Poncho
7
4
7
0
0
...Formerly Known as Drumthing
1
2
16
1
1
Triggo
15
4
1
1
1
Whammo
11
9
8
0
0
Whammy Bar
1
2
12
1
1
Results
Comparing the performance measures for robots sorted into weapon groupings of ['spinner'/'non-spinner'] and ['active'/'passive'] yields the following results by weight class:
Beetleweights
Robots
Mean Lifetime Match Win %
Mean BotRank [of 258]
Spinners
19
39%
129th
Non-Spinners
15
56%
84th
Active Weapons
22
39%
130th
Passive Weapons
12
61%
72nd
Only Wedges
10
65%
53rd
Featherweights
Robots
Mean Lifetime Match Win %
Mean BotRank [of 26]
Spinners
18
35%
15th
Non-Spinners
8
49%
11th
Active Weapons
20
37%
14th
Passive Weapons
6
49%
12th
Only Wedges
5
50%
11th
The bottom line is the same as it was ten years ago. In both weight classes the average spinner and the average active weaponed 'bot underperform their non-spinner and passive weaponed counterparts. Spinners trail in their percentage of matches won and in their scores at BotRank.
Discussion
On average, active weaponry offers no advantage in combat success in weight classes examined. However, even though the average beetle or feather with an active weapon performs less well than the average passive-weaponed robot, the top-ranked robot in each of these classes is a spinner. If you have an experienced team with ample resources and will settle for nothing but first place you will be best served to run with a spinner. But if you're an average builder who wants to win matches you'll be better off building a boring but capable wedge.
Run Amok Combat Robotics
