Version 12.1

This version is like a fresh breath of chaos. Oh, the mischief I'm causing. :P

One of the few altruistic bots: beating the strong and helping the weak ;-) But the overall result is ok, closing in on Dookious. If you can find a way to rule out those 98->75 scores you'll be close to #3 and way ahead of me.

I've been impressed with the improvements in GresSuffurd. It has inspired me in my efforts to improve XanderCat.

Nice work!

Though it looks like you still have a few bugs in your specialized modes. A 26% score against GeomancyBS is almost as bad as 70% against Idem (a nano with Linear Targeting).

UPDATE: Version 12.2 is much better against those two bots.

Indeed. There is still some room for further improvement if I can iron out those trouble areas without hurting performance elsewhere. I'm pretty sure it can be done.

Really nice work, congrats! I wonder if you've got Skilgannon thinking that maybe Bullet Shielding is the gateway to 91 APS - I know I'm thinking it. :-)

Indeed, seeing the diff between GeomancyBS and DrussGT has had me wondering about this for quite a while...

Wow... Should I just hold my congrats until you get to #1? =) Friggin' awesome!

Thank you. I really didn't expect to see such success with adding a new mode to XanderCat. But after a lot of work unsuccessfully trying to improve the main surfing drive, I have to say I'm most pleased with it. :)

I'm also surprised how much it helped. I also think there might be scope for the opportunity to open up a shadow enough to completely hide in it with regular surfing, rather than just have a separate mode. And to get the full magnitude of the improvement, I think this diff is more relevant, and even more impressive. Never mind 91APS, 92 could be a possible target.

Speaking of bullet shadows, I think active shadowing could be possible in a 1000/1000 field. It could be used in Melee endgame duels to great effect. First, check if a full shadow is possible, if it is, then fire a low power bullet to create the shadow and move accordingly. If a full shadow is not possible, then just surf and fire normally.

One problem I could see with this is that you might not gain any energy by firing 0.1 bullets, because at long distances in endgame, 0.1 bullets are pretty regular. Also, with the enemy also shooting low power, you won't have much advantage in distance ratios to get a wide shadow because of bullet speed differences, but with enough distance that shouldn't matter that much I guess. Hmm. Food for thought...

I'm not sure that's true (edit: active shadowing more effective on larger fields). Being far away means the shadow has had time to grow, that's true. But another key to creating big shadows is for the bullet/wave intersection to happen as soon as possible after the enemy wave is fired. The farther away you are, the harder it will be to do that with any precision. It might be more effective to stay close and create accurate shadows than to gamble from far away.

Edit: Sorry, my argument kind of misses the point. With Robocode accel/decel, it's more about giving yourself enough time to get there. So I think you're right.

I don't understand, I thought as long as there was a 36px area within reach that could not possibly be hit, a bot in that area would be completely safe.

You're right, I was being dumb.

I wonder if this full shield idea is applied in teamrumble. 1200x1200 battlefield and 5 simultaneous shots which can be coordinated to create huge shadows.

It isn't, but it sounds promising. It could also work in twin duel: take out the weak enemy then have your two bots shadow/shield each other until the enemy leader runs out of energy.

This would be tough in Twin Duel with the code size restriction. But I think MegaBot 2v2 would be interesting at this point.

Not necessarily. Make both bots instances of the same class, give them Waylander's gun, fire 3's at the enemy grunt until it's 1v2, then have them hide in corners and shield each other every time the enemy fires. I believe Rednaxela was planning to try something like this. Let's beat him to it! :)

In team battles, there is the added complexity (and fun) of needing near perfect team radar locks to make bullet shield viable.

Provocative movement, which owns bullet shield, is also a greater threat in team battles than it is in 1v1.

Neuromancer does 'bot-shadows', where if a wave passes over an enemy, the section that the enemy covered is marked as safe. Unfortunately it didn't help in terms of score, I suspect that my wave locations and firetimes aren't accurate enough. Also, if the wave was fired far enough away that it passed over another bot it probably wasn't weighted very highly anyway.

In the old days of robocoding, 'bot-shadows' were called bomb sheltering.

Ah, I knew I didn't come up with that idea independently...

One bad thing is that there is a lot more volatility in the score, based on whether or not the "scenario" (my terminology) correctly identifies which opponents to activate against. And the score difference can be huge. While in the past the Rumble score was pretty stable after about 2000 battles, I would say it now takes more like 6000 to 8000 battles. Watching the progression on version 12.2, after about 1200 or so battles the APS was around 86.85 (excitingly close to WaveSerpent), but now with 3800 battles it has dropped to 86.50, in danger of dropping below Dookious after such a solid first showing. I still don't think we can say whether or not it will level out above or below Dookious.

It should also be noted that the effectiveness of bullet shielding will be less if implemented by top surfers. The score boosts will be less against the vulnerable, and there is more opportunity to lose performance against the non-vulnerable.

I also have to take an extra step in future development. Due to the volatility, whenever I am working on anything but bullet shielding, I have to disable the bullet shielding mode to get more reliable testing results.

I know I am kind of focusing on the downsides here, but I think the upside is pretty obvious, thus I am commenting on the more subtle issues this new mode introduces.

After looking at the individual battles against a number of opponents, I might add that with more testing and time, I can probably improve the scenario to activate a little more reliably against vulnerable opponents. This could eliminate at least some of the volatility and possibly give another 0.2 to 0.3 APS boost (assuming 12.2 holds around 86.5). I will have to create a challenge of shielding vulnerable opponents and collect more diagnostics to see which of my conditions for continuing bullet shielding are occasionally violated and why; then I can hopefully tweak it a bit to make detection more reliable.

I've actually been thinking about this. It's not possible to know how well you can dodge their targeting without risking poisoning their targeting into shooting non-GF0 bullets, which makes it difficult to know against bots that you can dodge perfectly if they are secretly a Hydra, and the 97% is a 30% increase in possible score, or if they are just DoctorBob and the 97% is a 3% decrease in score.

That's true, but bullet defenses are very unexplored areas of Robocode strategy. Some sort of "Adaptive Bullet Shielding" could be very successful.

0.35 is a lot after 2k, and I would certainly buy that this increases your volatility, but I'd wait and see if future versions behave similarly to say for sure. I've seen lots of variance above 2k battles with lots of bots, not just after adding sensitive multi-mode stuff. It was something I never really noticed until we had a surge in RoboRumble power from KID's clients and bots started actually getting to 5k-8k battles. It could have also been something like a few enemy bots crashing/skipping turns on one client and then behaving normally on another client that started up later.