Elevators

I did some research into the elevators in Home Alone 2 and found a couple interesting things. First of all, where the elevator goes to changes every frame and cannot be manipulated. But you can affect how fast an elevator arrives at the destination floor.

I will talk about a couple things here:
* Waiting for the elevators
* How pressing A interacts with the elevator
* Recommended strat for the elevator
* The length of elevators between different floors
* Floor routing
* The speed of the elevators
* Advanced elevator strats


I'll talk more in-depth about the elevator mechanics at the end.

# Waiting on elevators
When you reach the elevators the game starts a 21 second timer. You need to press the elevator button within 4 seconds or else the game will add 4 more seconds to the timer. After the first button press, you have to wait about 19-20 seconds until the button works again. Once 19-20 seconds have passed, you need 4 more button presses before you can enter the elevator. A fifth press will also open the door, but this isn't needed. This will usually happen between 55 and 56 seconds into the run. 

# A presses and strats
## Pressing A while on the elevator
Once the game has loaded the elevator, the game starts an internal timer that goes from 0 to 47 (0.8 seconds), after which it resets. After this has happened 4 times, the door closes and the elevator starts going. However. you can speed this up by pressing A after 0.4 seconds. For you this means you should just mash the A button. 

When the elevator starts moving, this timer stays important. Every time the timer goes back to 0, it'll either change the floor number on the little screens or stop the elevator.


## Elevator strats
The old strat was to just mash until you exit the elevator, but this only works for about half the elevators. The problem is that when the game wants to stop the elevator, it slows down until it reaches its destination. This slow down can happen too early when you mash and can lose you 1 to 4 seconds.
Here are a couple videos that show when the mashing works, and other strats you can do: https://www.youtube.com/playlist?list=PLCognG8VGQx4kIA5R3pAGWp2vTlRtIIrC

Tl;dw
From the lobby:
As the elevator starts moving, you want to mash until the L on the screen changes to 11. When the elevator stops, you start mashing again. This will always give

From elsewhere:
Mash until the number on the screen has changed, then stop. Mash again when the elevator has stopped. This should give you good elevators when you move 2 or 3 floors. If you are 100% certain the elevator will only move 1 floor, you do nothing once the elevator starts moving and you mash when it has stopped.

After the elevator speed section I will explain the advanced elevator strat.


# Length of different elevators and routing
## Elevator times
Elevators take a different amount of time to reach the target floor, depending on how far it has to travel. Elevators that leave from the lobby work differently than all the others. This is how long they all take with frame perfect inputs:
* Lobby to floor 11: 4.467 seconds
* Lobby to floor 12: 5.333 seconds
* Lobby to floor 14: 5.317 seconds
* Lobby to floor 15: 5.750 seconds

* Between numbered floors, moving 1 floor: 5.800 seconds
* Between numbered floors, moving 2 floors: 4.467 seconds
* Between numbered floors, moving 3 floors: 5.350 seconds
* Between numbered floors, moving 4 floors: 5.300 seconds


## Elevator routing

With this we can find which route is the best. These seven are the fastest:
1. Lobby to 12 to 15 to 11 to 14 to 16
2. Lobby to 11 to 14 to 15 to 12 to 16 (0.50 slower)
2. Lobby to 11 to 15 to 12 to 14 to 16 (0.50 slower)
4. Lobby to 14 to 11 to 15 to 12 to 16 (0.85 slower)
5. Lobby to 15 to 12 to 11 to 14 to 16 (0.87 slower)
6. Lobby to 11 to 12 to 15 to 14 to 16 (0.90 slower)
6. Lobby to 11 to 14 to 12 to 15 to 16 (0.90 slower)

As you can see, Lobby to floor 11 as your starting elevator gives you the highest chance for a fast route.

# Speed of Elevators and advanced strats
##Elevator speed
Elevators also move at a different speed when they start. The more floors they have to go up or down, the faster it goes. Once you have learned to recognize which speed belongs to which elevator, you can use it to change your A presses. 
Here's a video comparing all the elevator speeds: https://youtu.be/J2tTHmxzJl8

## Advanced elevator strat
For the elevators that leave from the lobby, a recommended strat is to mash until the floor number changes to 11 and then change what you do based on where you're going:
* 11 and 12: stop mashing until the elevator has stopped, then continue mashing.
* 14: Mash A all the way to the end.
* 15: Mash A until the number has changed to 14, wait a little bit. Then press A once. Wait a little bit again and then mash when the elevator has almost arrived.
https://youtu.be/W7J6hGgfk08

For the other elevators this won't work as well, because if you only travel 1 floor, for example 11 to 12, you do not want to press A at all when the elevator is moving. If you do, you'll slow it down early and lose a lot of time on an already slow elevator. So there's still some RNG there. 

# Other
Here's all the elevator routes that are within 2 seconds of the fastest:
https://i.ibb.co/J5GwhV3/Home-Alone-2-Elevator-routes.png

## Elevator mechanics in-depth explanation
First of all, the destination floor depends on the frame you enter the elevator. Going up by 1 floor would make sense as the fastest way to progress through the hotel, but because of the way the elevators work it isn't. I'll get back to that later.
Once the game has loaded the elevator, the game starts a timer that goes from 0 to 47, after which it resets to 0. The cycle needs to be completed 4 times for the door to close and the elevator to start going. After this, a completed cycle will do one of two actions: it will either change the floor number on the screen, or slow down the elevator to prepare to stop.
For example, when traveling from floor L to floor 12, the game will need to complete 3 cycles of the elevator timer. First to change the floor number to 11, then another one to change it to 12 and the final one to stop the elevator.
This cycle can be completed early by pressing A. This can only be done after 24 frames, so on 0-23 nothing happens, but on 24-47 the timer will reset to 0. With specific A presses, we can minimize the time the elevator needs to reach the target floor. The final A press (or completed cycle) needs to be as close to the stopping point as possible, otherwise the elevator will slow down early and lose time. The A press can sometimes be adjusted to line up with the timer for the door opening as well.
After you've arrived at the destination floor, you once again need 4 completed cycles to open the door, same as closing it.

## Floor routing in-depth explanation
In some cases, the elevator timer will slow down the elevator too early. This is the case when moving a single floor between the numbered floors, which is why Lobby to 11 to 12 to 14 to 15 to 16 is not the fastest route. So we need to find the fastest route. To make matters more complicated, the Lobby elevator behaves differently to all the other ones. This is how long each elevator takes: 
* Lobby to floor 11: 268 frames 
* Lobby to floor 12: 320 frames 
* Lobby to floor 14: 319 frames 
* Lobby to floor 15: 345 frames 

* Between numbered floors, moving 1 floor: 348 frames 
* Between numbered floors, moving 2 floors: 268 frames 
* Between numbered floors, moving 3 floors: 321 frames 
* Between numbered floors, moving 4 floors: 318 frames 

You always start from the Lobby and finish at floor 16. Elevators going down take 1 more frame than elevators going up, this is because of the game spending 1 frame to change the arrow from up to down.
The fastest route is: L > 12 > 15 > 11 > 14 > 16 (320 + 268 + 321 + 268 + 268 frames). The next best route is 27 frames slower.

I hope this helps people to understand how the elevators work. If you have any questions, feel free to DM me.

ScarfaceNico

Home Alone 2 (NES)

Nintendo Entertainment System

mikesneslive

RyuHayabusa89

smartalec24

aaron2u2

USA / NTSC

Home Alone