XanderCat

MegaBot based on my "Xander" robot framework with pluggable guns, radars, and drives. Currently using BasicRadar, IdealPositionDrive, AntiMirrorDrive, StatDrive, StatGun, AntiMirrorGun, LinearGun and CircularGun.

Versions up through 2.1 and from 3.1 onward are handcrafted without borrowing code or ideas from other robots. Version 3.0 uses a variation on the Wave Surfing drive from BasicGFSurfer, but a wave surfing drive of my own design is used in version 3.1 and beyond. XanderCat could be made smaller by removing unused Xander components and taking advantage of some of the newer classes like Rules, but it's so far above the next smaller weight class that it doesn't really matter.

Current Version: 3.4

Best against: Any robot that spends too much time standing still, going straight, going in circles, or doing basic mirroring.

Worst against: Well...that uCatcher bot. What's up with that one? The more I improve overall, the worse my performance gets against it.

Version Notes

Version Ranks

Note: Best Change and Worst Change are the change from previous version against the given opponent.

Version	1-on-1 Rank	Top	Best Change	% Score Change	Worst Change	% Score Change
1.0	~475 / 805	59%	N/A	N/A	N/A	N/A
2.0	386 / 806	48%	mld.Wisdom 1.0	4.18 -> 76.13	SuperSample.SuperCrazy 1.0	61.97 -> 37.00
2.1	320 / 805	40%	dz.MostlyHarmlessNano 2.1	20.90 -> 63.01	jf.Dodger 1.1	78.98 -> 41.10
3.0	148 / 805	18%	gg.Wolverine 2.0	41.08 -> 94.57	xiongan.Xiongan 1.1	100.0 -> 74.39
3.1	145 / 804	18%	zyx.nano.RedBull 1.0	53.4 -> 85.3	pulsar.PulsarNano 0.2.4	89.3 -> 64.2
3.2	116 / 806	14%	ags.polished.PolishedRuby 1	28.5 -> 83.5	rsim.micro.uCatcher 0.1	91.7 -> 31.8
3.3	115 / 806	14%	nat.Samekh 0.4	24.9 -> 64.9	simonton.micro.GFMicro 1.0	62.2 -> 39.2
3.4	85 / 806	11%	dsx724.VSAB_EP3a 1.0	67.2 -> 93.4	intruder.PrairieWolf 2.61	65.6 -> 48.4
3.5.1	94 / 805	12%	rsim.micro.uCatcher 0.1	21.3 -> 96.4	nat.BlackHole 2.0gamma	69.2 -> 42.5

Version 1.0

Based on a not-quite-complete Xander framework. Uses BasicRadar, OrbitalDrive, and a CompoundGun combining a CircularGun and a LinearGun.

Version 2.0

This version adds a StatGun to the CompoundGun (in order, the CompoundGun will consist of a StatGun, CircularGun, and LinearGun). The StatGun is a "Guess Factor" gun of my own design. I don't call it "Guess Factor" because, frankly, I hate that term. The stat gun supports variable configuration, with interchangable Segmenter modules. Version 2.0 uses a CompoundSegmenter, which combines a BulletTravelTimeSegmenter and a RelativeDirectionSegmenter. This segmenter combination categorizes the statistics based on approximate time it takes bullet to reach opponent and opponent heading relative to self.

Version 2.1

Version 2.1 adds better gun selection, tweaked parameters for firing, driving, and stat gun segmenting. For the driving, it drops the "inverse gravity bullet dodging", as it assumes opponents are using head-on or linear targeting, which likely causes worse performance against opponents using guess factor guns. Instead, it just randomizes movement a little more.

Version 3.0

This version drops the Orbital Drive, and instead uses a Wave Surfing drive based on the drive used by the BasicGFSurfer. This means I cannot credit myself entirely for this version, as I am using a modified version of a previously existing Wave Surfing drive. This version will serve as a reference point for my next version, which will use a Wave Surfing drive of my own design.

Version 3.1

Switched to using my StatDrive for driving, a form of wave surfing drive of my own design. This drive has not been tweaked yet, but seems to be doing it's job well so far. Will be interesting to see how it compares to version 3.0 in the rumble. This version also takes advantage of the ability to paint on the battlefield (very cool!), though it is disabled in the packaged form. It also benefits form a few minor tweaks to the Xander framework, for things like firing at enemies who are low on energy or disabled.

Version 3.2

This version has the following modification from version 3.1:

• Flattening turned off in StatDrive
• Now tries to better position itself on round start using IdealPositionDrive (before bullets start flying)
• StatDrive now attempts to back away from the enemy/enemy waves if it deems itself too close
• Anti-Mirror components added (a drive, gun, and a few other odds and ends). Bye bye PolishedRuby 1; I was tired of you wiping the floor with me. :-)

Version 3.3

This version has the following modifications from version 3.2:

• StatDrive Flattening now auto-enables after a particular point in time if the opponent's hit ratio is over a certain threshold.
• StatGun segmentation changed a bit; fewer relative direction and bullet travel time segments, but added a drive speed segmenter.
• StatGun now does a better job of predicting how far an opponent can get, and only looks within that range when deciding where to fire.
• Some other minor StatGun tweaks.

Version 3.4

Version 3.3 didn't show the improvement I was hoping for. My next step was to do some bug hunting. This has revealed a few things which have resulted in the following changes:

• StatDrive previously would decide on where to go for a bullet wave repeatedly. While this might would seem good in that it makes it arguably more adaptable to unexpected events, that potential advantage appears to be outweighed by the "flip flopper" effect. In some cases, XanderCat would keep changing it's mind on which direction to go for a wave, making it more likely to get hit. Amusing, but not what I'm going for. To avoid this problem, I have changed it so the decision on where to go for a wave is made once, and XanderCat sticks to that decision until the next wave.
• StatDrive would previously go to the division of least danger. I've found this to be too simple in practice. I've now changed it so it separately looks clockwise and counter-clockwise, computing the average danger in each direction, and finding the exact division of least danger in each direction. If one direction has significantly lower average danger than the other, the exact division of least danger in that direction is chosen. If the two average danger levels are close to equal, it then chooses by which individual division has the least danger. If the individual danger levels are close to equal, it then randomly decides.
• Flattening effect has been turned off.
• Rolling danger levels has been turned on (note: danger levels are only rolled when total danger for a segment reaches a set maximum value)
• The number of drive segments has been reduced slightly.

Per the advice of others, I looked deeper into the performance against HawkOnFire and Barracuda. Some of the above changes are based on that. My current scores against (in my own testing) against HawkOnFire and Barracuda average about 98% and 95% respectively.

For kicks, I left on the painting features, in case anyone wants to see what I have been playing with. :-) I don't think it degrades performance too much, as most of the work happens in the onPaint method which is bypassed when not turned on the the UI.

Rumble Results

XanderCat 3.4 places 85th in the Rumble. To someone not familiar with Robocode, that might sound kind of bad. But to those who are familiar with Robocode...well, I can't speak for the rest of you, but I think it's pretty darn good. It achieves my early goal of reaching the top 100.

Version 3.5

This version has the following changes from the previous version:

• Mostly fixed bug with gun aiming where aim was always one tick behind. Fixed this by aiming with predicted positions 1 tick into the future, though this won't be exact.
• Future position prediction bug fixed (was not taking velocity into account when changing heading).
• StatGun overhaul. I have attempted to make it as precise as possible. Changes to the StatGun include the following upgrades:
  • Segment "danger" is now added as a triangular region in the factors/divisions centered at exact sighting factor rather than at a fixed sighting factor (in other words, the values added to the bins approximates for the exact sighting location rather than centering at the center of the closest factor; I'd have to include a picture, as it is hard to explain). The triangular region added adjusts based on robot width (when a robot is closer, it's width causes it to span more divisions).
  • When getting the factor angle for a particular factor index, it now estimates an exact factor by considering the values in neighboring bins rather than taking the factor angle for the center of the pie slice for the factor index.
  • It now attempts to get state of opponent when my bullet wave hits them down to the partial tick.
  • Rolling history added.
• Xander framework cleaned up and documented a little more.
• Some segmentation changes on the StatGun. Now using lateral velocity, and wall smoothing (or wall proximity).
• implemented a victory move when it wins. (because I can, though Robocode usually cuts the performance short)

The main purpose of this version is to see how much an improvement I can make just by polishing my guns.

Left out of this version (and possible changes for next version):

• Drive flattening in special cases
• Dive protection
• The Red Eyed Monkey

Rumble Results

Version 3.5 had a couple of bugs that were causing it to crash hard. I found the bugs and updated it. Waiting to see how 3.5.1 does.

Performed worse than 3.4. The problem I believe is a combination of 2 factors -- my segmentation isn't right, and my mix of guns is throwing things off. I believe by continuing to allow other guns to fire, it is polluting the statistics of the stat gun (the stat gun still records everything, but the opponent behaves in a less predictable fasion).

Version 3.6

This version will include the following changes from the previous version:

• Linear and Circular guns are only be used if their hit ratio early on is very high.
• New higher quality segmentation processing for the guns allowing for the comparison of segment combinations on the fly.
• Gun segmenters in use changed to lateral velocity, bullet speed, and wall smoothing (wall proximity).

Other Versions

I may release various other minor versions that are just tweaks and bug fixes. There are a number of configurable parameters I could play with. I might also update it specifically for melee and enter it in the melee rumble.