Run Amok Combat Robotics
What Weapons Win -- Active Weapons versus Passive weapons

There is a perception in the robot combat community that robots with spinning weapons ('spinners') and other types of active weaponry (lifers, flippers, etc.) win more matches than do wedges, rammers, and other non-active types of 'bots. To inject a little substance into the discussion, I ran a statistical analysis of tournament outcomes for 2005.

Note: an update of this analysis based on 2015/2016 data is available: What Weapons Win 2016

 


   Method

I selected the 12-pound 'hobbyweight' and 3-pound 'beetleweight' class robots for this analysis because they are popular and are commonly represented at events.

I examined the lists of entered 'bots from the 'completed events' listed on the 'events' page of buildersdb.com on December 12th, 2005 and recorded the weapon type for each hobbyweight and beetleweight robot that competed in any of the twenty events listed. Those events were:

DaVinci Days
Summer W.H.R.E
Robot Rebellion 5.3
SNF Qualifier 1.0
POP9 Worst Ever
WBX-II
Last Chance
RoboPraxis
TCO III
Underground Rampage
Robonexus
BBS3 - Alien Invasion
Robothon
House of NERC 2005
Detroit Bug Battle 3
Fall W.H.R.E. '05
Robot Rebellion 5.4
2005 RFL Nationals
Combots Cup
Bay Area Robot Fights

I then went to Botrank.com and recorded the win/loss record and ranking for each of the beetleweight and hobbyweight 'bots from the above events:

Beetleweights
Name Wins Losses Rank Spinner Active
 3A 2 5 137 1 1
 3pd 17 4 2 1 1
 Aim N Maim 3 2 42 0 0
 Altitude 2 1 45 1 1
 Anthrax 4 2 27 1 1
 Beetle from Hell 13 12 38 0 0
 Box of Death 4 4 48 1 1
 Buster Blade 14 3 3 1 1
 Buzz 0 2 128 1 1
 Cannon Fodder 4 0 13 1 1
 Creepy Crawler 2 2 48 0 0
 Dark Slayer 2 2 51 1 1
 Enemy 1 2 103 1 1
 Fear Factor Sr. 1 2 79 1 1
 Fear Factor Sr. 2 7 6 33 1 1
 Fir Darrig 15 11 16 0 0
 Fire Fly 4 2 28 0 0
 John Henry 4 2 22 0 0
 Mars Attacks 2 0 2 120 1 1
 Mini Spar-Kee 13 4 4 1 1
 Nemo 6 6 36 1 1
 Nuclear Kitten 9 1 6 1 1
 OFUC 15 2 1 1 1
 Pop Goes the Monkey 2 0 29 0 1
 Pyramid of Death 13 10 24 0 0
 Ripblade 1 4 136 1 1
 Ron 8 1 8 1 1
 Sandman 5 6 86 0 0
 Sawtooth 8 0 5 1 1
 SLS 4 5 107 1 1
 Spinny Thing of Doom 3 4 70 1 1
 Ultrabot 1 2 105 0 0
 Unknown Avenger 2 6 139 0 1
 Unlettered Understrapper 2.0 0 2 125 1 1
 VDB 5 2 15 1 1
 Vengence is Mine 0 2 109 1 1
 Wheelie 4 6 114 0 1
 Woodchuck 3 4 85 1 1
 Wrath of Abomination 0 2 126 1 1
 Zap 9 8 34 0 0

Hobbyweights
Name Wins Losses Rank Spinner Active
 All Hail Kitty 4 6 82 0 0
 Bullet 7 4 8 0 1
 Cantankerous Cowpoke 3.1 0 4 117 0 0
 CheepShot 3.0 12 5 9 0 0
 Chigger 26 11 2 0 0
 Dexahedron 3 1 19 1 1
 Gamma Knife 2 4 90 1 1
 High Gravity 0 2 111 1 1
 Lil Shocker 20 7 4 0 0
 LittleBytes 1 2 58 0 0
 Mad Mennonite 0 2 87 1 1
 Mad Puppy 1 6 123 1 1
 Rants Pants 5 4 33 0 0
 Rellik 1 8 124 1 1
 Ricochet 11 6 10 0 0
 Scoopula 5 6 53 0 0
 Sir Nuts 'n' Bolts 1 2 66 0 0
 Skittlebrau 1 4 113 1 1
 Spatula 15 10 11 0 0
 Target Practice 17 6 5 0 1
 The Prussian Pitchfork of Pain 2 2 52 0 0
 Toxic 5 6 54 1 1
 Trivial 1 2 79 0 0
 Wedgio 14 4 6 0 1


   Results

Compiling the combat records of the robots into with/without spinner weaponry, and with/without the broader 'Active' weapon category (includes lifters, clampbots...) yields the following results by weight class:

Beetleweights Robots Median winning percentage Percent with winning record Mean ranking
With spinning weapon 27 50.0% 44.4% 60th
Without spinning weapon 13 52.9% 61.5% 56th
With active weapon 30 50.0% 43.3% 63rd
Without active weapon 10 54.7% 70.0% 44th

Hobbyweights Robots Median winning percentage Percent with winning record Mean ranking
With spinning weapon 12 33.3% 22.2% 80th
Without spinning weapon 12 55.6% 53.3% 40th
With active weapon 15 39.4% 41.7% 62nd
Without active weapon 9 47.5% 41.7% 48th

  • The median hobbyweight and beetleweight combat robots without spinning weapons have a higher percentage of wins than do the median hobbyweight and beetleweight robots with spinning weapons. They also have a higher percentage of winning records and a higher mean botrank.com ranking than their spinning-weaponed conterparts.

  • The median hobbyweight and beetleweight combat robots without active weapons have a higher percentage of wins than do the median hobbyweight and beetleweight robots with active weapons. Thay also have an equal or higher percentage of winning records and a higher mean botrank.com ranking than their active-weaponed conterparts.


   Discussion

On average, active weaponry appears to have no advantage in the success of the combat robot classes examined. However, although the average hobbyweight or beetleweight combat robot with an active weapon performs less well than the median robot without an active weapon, there is an elite group of spinners and lifters that dominate the upper rankings of both weight classes. These elite robots are built and operated by experienced teams with no shortage of resources.

If you have the experience and skill to properly construct and operate a 'bot with an active weapon, the effort may be worthwhile. If you are new to robot combat or have limited resources, stick to simpler robots.


   Questions

Email: joerger@toast.net


Copyright 2006 -- Mark Joerger, Team Run Amok

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