1 – A TAS is only as good as the person who created it. As such, they are not necessarily “perfect” for any game, and are only the sum total of what is known at the time of creation. Any new discoveries, at any time, can invalidate any claims of “perfection” on any TAS ever created. That is just the nature of the evolving game.

2 – Contra's Beating Heart – Contra seeds itself with your inputs, literally adapting to your play. This mostly effects the spawning of lag trolls, but also has a part in the Snow Field boss spawn location and JJ's patterns of attack (Energy Zone Boss). That is why it feels like doing the same exact things renders the same exact results. It does. But this mechanic is “frame perfect”, and even a single frame varied can change what's coming in the near future. It is important to note that whatever this “seed” value is, it resets at the start of each level.

3 – Waterfall and Ledge Skips – This is difficult to explain properly, but I will try my best. First, lets call the thick green ledges we're running on 1 high. That's the entire platform. Your “normal” jump can get you onto a platform 3 High. Ledge Skips get you on to platforms that are 4 high. A Ledge Skip can only occur where you can land moving right and make an entire jump moving right, corresponding with a correct value for your jump (0094 in Memory Viewer – I simply call it “Jump Value”) that changes with every jump you make, and also with every movement you make in the air above a certain height.

There are a number of values that allow you a “Ledge Skip Jump” that can clear 4 high ledges, but only one specific value will work on any given jump. Due to the nature of these variables, my method for discovering the ledge skips in my route was simply brute force. There are, in my estimation, nine total ledge skips that can be achieved in a single run. However, due to human patience limitations, 5 was the best I could do on this effort.

Given how precise these variables are, it really opened my eyes to how skilled our Contra runners are. Even repeating the current “2 Ledge Skip + No Fire Jump” route is very difficult.

4 – Tight Jumps

Jungle: “The Jungle Jump” - 3 Frame Window - After avoiding the “L”, getting the “R”, and killing the turret, there is this first difficult jump of the game. This is the most practiced tight jump in Contra and it has the benefit of a visual edge to jump from. It is better to miss this one late, as falling lets you catch the platform below. Doing so loses 0.3 over the 0.7 you'll lose jumping early and pulling back.

Waterfall: “Ledge Skips” - Frame Perfect Variable Setup – Ledge Skips are covered above.

Waterfall: “Fire Jump” - Varies between 3 and 7 frames depending on if you have a ledge skip jump loaded up or not. One of my least favorite jumps in the entire game, as you are jumping over something moving toward you on the platform above you. This jump is unnecessary in the current routing, but is still good to know.

Snow Field: “Two Bomb Jump” - 3 Frame Window – This infamous run destroyer is actually a 3 frame window like the Jungle Jump, but doesn't have any visual markers to jump from unless you use the far right tree somehow. I personally use the audio cue.

Energy Zone: “Frame Flame” - Frame Perfect – At the vertical flame where we all simply take a split stop before jumping over the pit, you can hit a frame perfect jump here without stopping at all. Worth it? Probably not. xD

Energy Zone: “The Exo” - 15 Frame Window over 5 Jumps – 3 Frame Drop Window – The Exo is pretty well documented. I was able to do little other than verify known information. You can pause buffer all of the horizontal fire pillars in this section if needed.

Enerzy Zone: “The Leap of Faith” - 18 Frame Jump Window – Random Overhead Fire Pillar Timing – This is actually pure RNG seeded by your inputs and is not on either the Global or Proximity Timers. I was able to manipulate the overhead pillar in a similar way to lag trolls, but that doesn't help the player in real time. There is no good way to do this, and thus, “Leap of Faith” is an apt name. If you choose to take this jump, there is a very high chance that you'll die.

Energy Zone: “Frame Flame 2” - 3 Frame Window – The very last vertical pillar before JJ has a 3 frame window between getting killed by the fire and losing forward frames to the ledge. Still better to miss this one late.

Hangar: “Cart Catch” - 22 Frame Jump Window on to the Cart – After getting the “B”, you'll come to the gap with the cart on the other side. It is not a hard jump, but listing here because every frame you are late costs you a frame of forward movement on top of the cart. Doesn't equal much in real time, but every little bit helps.

5 – Pause Buffering – I once thought pause buffering to be a frame perfect thing. It is not. The game only has to be paused when the “target” goes off to cancel it. A Pause Buffer can be used on anything triggered by the Global Timer. This includes many flame pillars in Energy Zone and almost all of the Hooks in Hangar. A perfect pause buffer is a 3 frame loss, but in reality, a human pause buffer looks more like 6 or 7 frames, as frame perfect isn't a human thing most of the time. This trick is very powerful, and should be mastered by every runner, even if it feels cheap. It can save runs, but it does cost time to use.

6 – The Cost of Missing – Most of us simply pound away on bosses, as our mash is ballistic. But when your mash gets over 8 per second or so, those missed shots on bosses you're right up against can cost you quarters of a second at a time. I've seen one missed bullet cost me 24 frames in extra button presses against the Dogra's in Snow Field. I've seen one missed bullet cost me 15 frames in extra presses against Falcon's Heart. I know it seems ridiculous, but the cost of missing shots on the bosses you pulverize is actually quite steep. 15 frames is 0.25 seconds.

As always, any questions you may have are welcome. I will try to answer them to the best of my ability.

Thank you for your time!

Great write-up. Too bad it doesn't help with my awful mashing speed :P