e.getVelocity() * Math.sin(e.getBearingRadians() - e.getHeadingRadians())
the speed at which the enemy is strafing relative to you. -or- the speed at which the enemy is moving perpendicular to you.
This is the information used in most nano PatternMatchers. It is good for matching an enemy's movement as long as their movement is relative to your own position. I think if you put a nano pattern matcher in the PatternMatcherChallenge it would do very poorly, since the reference bot's movement completely ignores you.
I think thats called Lateral Velocity, by most robocoder's. --Chase-san