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While that would minimize the codesize, it would make the wall avoidance much more pronounce (and much worse).

I come back time to time to see if I can make a better wall avoidance for this robot. But so far I have failed terribly.

ahead(.222222 * (direction = -direction));

And here I was hoping you would come up with some amazing wall avoidance technique. :)

That's probably more in Mike's territory, but I could give it a try.

Thanks for the attempt. I think I covered most possibilities already however. Unfortunately it only has about 50 bytes to play with.

How does this look? It will hit walls when it doesn't have enough time to turn, but it doesn't stick on them. If there were only eight bytes to spare I could make it slow down when it had to make a wide turn, which would greatly reduce the number of wall hits.

package cs;
 
//import java.awt.Color;
import java.awt.geom.Point2D;
import robocode.AdvancedRobot;
//import robocode.HitWallEvent;
import robocode.ScannedRobotEvent;
import robocode.util.Utils;
 
/**
 * Talon - a Nano Melee robot by Chase
 * 
 * The idea is to avoid driving toward enemy robots, nearer ones are more
 * dangerous to drive towards.
 * 
 * Codesize: 247
 */
public class Talon extends AdvancedRobot {
	private static Point2D.Double[] map = new Point2D.Double[10];
	private static int n = 0;
 
	public void run() {
		//setAdjustGunForRobotTurn(true); //Sheldor: In melee this doesn't really matter.
		//setAllColors(Color.RED); //Sheldor: I'm very sorry. :(
		double angle, bestDanger, danger;
		while(true) {
		
			setAhead((bestDanger = angle = 360) /*- (3 * getTurnRemaining())*/); //Sheldor: Slowing down before making big turns makes the wall avoidance much better, but it costs ~8 bytes.
			
			while(angle-- > 0) {
				int t;
				setFire(t = getOthers()); //Sheldor: From Graviton.
				
				//Sheldor: Drive toward the center of the field when the bot gets near a wall.
				//This will only work properly on a 1000/1000 pixel field.
				danger = -Math.abs(Utils.normalRelativeAngleDegrees(angle - Math.toDegrees(Math.atan2(getX() - 500, getY() - 500)))) *
					((short)(table.charAt((int)getX()) + table.charAt((int)getY())));
					
				try {
					while(true) {
						// our most recent scans, unfortunately not enough room
						// to project them
						Point2D.Double v = map[--t];
						// set our gun to face this nearest enemy
						setTurnGunRight(Utils.normalRelativeAngleDegrees(v.y - getGunHeading()));
						// the difference between current angle we are
						// considering and the enemy
						// multiply it by how close they are, closer is more
						// dangerous to move towards
						danger += 1 / (Math.abs(Utils.normalRelativeAngleDegrees(angle - v.y)) + 1) / v.x; //Sheldor: "X / Y" has exactly the same effect as "X * (1 / Y)" but is ~3 bytes smaller.  
					}
				} catch(Exception e) {
					// We don't have room for any kind of sanity checks, also
					// the only way to get out of the loop without
					// having to have a comparison, saves us some code size
				}
				if(danger < bestDanger) {
					bestDanger = danger;
					setTurnRight(Utils.normalRelativeAngleDegrees(angle - getHeading()));
				}
			}
			// Turning it by only 1 saves us some code size but in radians this
			// value > PI/4 the maximum
			// turn the radar can turn, meaning it will cover the full arc as
			// long as we call it every turn.
			turnRadarRightRadians(1);
		}
	}
 
	public void onScannedRobot(ScannedRobotEvent e) {
		try {
			// Set the most recent scan into our map of enemies
			map[--n] = new Point2D.Double(e.getDistance(), getHeading() + e.getBearing());
		}
		catch(Exception ex) {
			// attempted to scan but it failed, set the number of enemies again
			// we miss an enemy scan but we gain some code size here
			n = getOthers();
		}
	}
	
	static final String table = "\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064" +
			"\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\u0001\u0001\u0001\u0001\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064" +
			"\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064" +
			"\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064";
}

It still seems to hang up on walls fairly easily. Sometimes it looks very nice and avoids them. But sometimes ti drives straight into them and hangs up on them.

But the idea isn't a bad one at all.

package cs;

import java.awt.geom.Point2D;
import robocode.AdvancedRobot;
import robocode.ScannedRobotEvent;
import robocode.util.Utils;
 
/**
 * Talon - a Nano Melee robot by Chase
 * 
 * The idea is to avoid driving toward enemy robots, nearer ones are more
 * dangerous to drive towards.
 * 
 * Codesize: 248
 */
public class Talon extends AdvancedRobot {
	private static Point2D.Double[] map = new Point2D.Double[10];
	private static int n;
 
	public void run() {
		//setAdjustGunForRobotTurn(true); //Sheldor: In melee this doesn't really matter.
		//setAllColors(Color.RED); //Sheldor: I'm very sorry. :(
		double angle, bestDanger, danger;
		while(true) {
		
			setAhead((bestDanger = angle = 360) - (5 * getTurnRemaining())); //Sheldor: Slowing down before making big turns makes the wall avoidance much better.
			
			while(angle-- > 0) {
				int t;
				setFire(t = getOthers()); //Sheldor: From Graviton.
				
				//Sheldor: Drive toward the center of the field when the bot gets near a wall.
				//This will only work properly on a 1000/1000 pixel field.
				danger = -Math.abs(Utils.normalRelativeAngleDegrees(angle - Math.toDegrees(Math.atan2(getX() - 500, getY() - 500)))) *
					(table.charAt((int)getX()) + table.charAt((int)getY()));
					
				try {
					while(true) {
						// our most recent scans, unfortunately not enough room
						// to project them
						Point2D.Double v;
						// set our gun to face this nearest enemy
						setTurnGunRight(Utils.normalRelativeAngleDegrees((v = map[--t]).y - getGunHeading()));
						// the difference between current angle we are
						// considering and the enemy
						// multiply it by how close they are, closer is more
						// dangerous to move towards
						danger += 1 / (Math.abs(Utils.normalRelativeAngleDegrees(angle - v.y))) / v.x; //Sheldor: "X / Y" has exactly the same effect as "X * (1 / Y)" but is ~3 bytes smaller.  
					}
				} catch(Exception e) {
					// We don't have room for any kind of sanity checks, also
					// the only way to get out of the loop without
					// having to have a comparison, saves us some code size
				}
				if(danger < bestDanger) {
					bestDanger = danger;
					setTurnRight(Utils.normalRelativeAngleDegrees(angle - getHeading()));
				}
			}
			// Turning it by only 1 saves us some code size but in radians this
			// value > PI/4 the maximum
			// turn the radar can turn, meaning it will cover the full arc as
			// long as we call it every turn.
			turnRadarRightRadians(1);
		}
	}
 
	public void onScannedRobot(ScannedRobotEvent e) {
		try {
			// Set the most recent scan into our map of enemies
			map[--n] = new Point2D.Double(e.getDistance(), getHeading() + e.getBearing());
		}
		catch(Exception ex) {
			// attempted to scan but it failed, set the number of enemies again
			// we miss an enemy scan but we gain some code size here
			n = getOthers();
		}
	}
	
	static final String table = "\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064" +
			"\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" +
			"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\u0001\u0001\u0001\u0001\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001" +
			"\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0001\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064" +
			"\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064" +
			"\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064\u0064";
}

Well it still knocks into walls a good bit, but less then my prototype. But it doesn't hang up on them either. Which is nice. If you are okay, we can brand it wiki or a cs.sheldor and enter it. See how a nano Minimum Risk Movement does.

The table could use a bit of tweaking, and I have a weird feeling that there's something better right under my nose, but let's go ahead and release it.

I'd be happy with just a mention in the comments, but I like the sound of cs.sheldor.Talon. Or, since we are both from the USA, we could emulate Nemo and name it usa.Talon. Whichever you prefer.