Hi I'm Lexam, and even though I'm not super good at this, I want to try my hand at theorizeing. I figure most theories are wrong so my awfulness won't stand out too much.
So what's the deal with the hand number? It must have some meaning after all numbers are quantatative they represent things. From what I've seen online the current theories are A) it's a ranking system, B) It's the amount of people left alive on the train, C) Seat number, D) Infractions.
Addressing these things in order
A) There hasn't been any cause for Tulip to jump four places. The idea would be that her interaction with the Steward caused the shift. However I would question how this ranking proceedure works. She didn't defeat the Stewart, it ran away on it's own after either the appearance of 1-1 or Atticus fixing the water. I feel the former is more likely which would give no indication as to the cause of a ranking change. If the latter it could be that since Atticus fixed the car's maintenance issue Tulip was ranked higher, but then why have a Steward to act as a mechanic. Assuming that there was a reason for increase why four places?
B) Four people died simultainiously for the first time in one week. Seems unlikely.
C) Why would a seat number change. You could argue maybe a kind of punishment but then her number would increase wouldn't it? First class is at the front. In addition which car is this seat in? or is the entire car her seat?
D) Why would they give 53 chances but take away 4 chances when meeting?
Now we come to the main point of this post, the crescendo if you will. I believe that the number on Tulips hand is the route code. First thing to note, the train itself is not infinitely long. We know this because if the train was infinitely long there would be no beginning or end. A front is clearly shown in the beginning of the video, but then why is it called the “infinity train”? If you notice in Corginia the wall of the train car is damaged, containing a hole through which the Stewart ran away. The hole contains nothing but blackness whereas the outside world is clearly a desert. Combined with the fact that Cirginia is clearly bigger that the car itself, it is likely that there is some sort of pocket dimension like box, inside each boxcar. In addition based on the Steward's actions, it's possible to travel outside and probably between each pocket box. Which brings me to my proposal of the infinite meaning. The train itself is not infinite but the amount of pocket boxes are. Corginia is not located in the 103rd or whatever that specific number box car is. The door simply connects to one of the many pocket boxes creating some kind of portal. How does the door figure out which pocket box to connect to, well this is where the hand-number comes into play. Trains have a four digit reporting number. The first number is to symbolize the type of train. This could or could not exist, but because the show is called infinity train and not infinity trains, I'm going to guess that this is the only kind of this train, meaning there would be no need for a class number because it is not part of a class. The second digit is the letter describing destination. This one is also difficult because we don't know if the train is going somewhere, or if it goes on for infinity. Since we have no evidence of the train having a destination, and there is no mention of the train stopping in the week Tulips been there, I am going to assume the train doesn't go anywhere so there would be no need for the train to have a destination letter. That leaves us with the 2-digit headcode which is either the individual train number, again pointless because it's a unique train, or it can be the route number. That route number is what I the number on her hand is. It is unlikely that the number has anything to do with the cars because she travelled through the car without a number change. The number change occurred after the Steward told Tulip to return to her seat and left. The Steward was the only change from the regular beat of the trip indicating it caused the change. In this case I think the Steward used it's mechanical abilities to change the route which Tulip was taking from the 53 to the 49 route which may be a more direct route to the seating area. This would explain a four digit jump because route wouldn't have any linear relation. In addition this explains why you could have a unlimited number of pocket boxes but a limited number of cars. There could be a infinite number of routes with a limited number of cars.This hypothesis would also give Tulip a end goal, at the begining of the train.
Note from the author:
Thanks for reading this, it's my first attempt and I hoped you liked it. If you have any critique, commentary, or advice I'll be happy to hear it. I hope this show gets greenlit so we can theorize as a community more. Thanks again for your time.