#1. By now a lot of people (Jennyfluff 2 years ago, and Marcel <2 months ago) have noticed that in OpenRCT 2 Fast-Forward% runs, the maximum speed at which the game will run depends on technical factors, like your hardware and other processes being run simultaneously (e.g. recording software).

-The same is true of normal speed.- If anyone gave you a specific time for ANYTHING, preface it in your mind with "around," "about," or "approximately."

Examples: Marcel stated in RCT 1 Park Value is recalculated every 12.8 seconds. Your time may vary. There's plenty of evidence against a fixed 12.8s already on this site. In a video, Marcel gives the length of a day in RCT as 13.21 or 13.65 seconds, depending on the number of days in the month. I timed how long it takes to get to 28 May (the day you unlock the 10th coaster) in an empty Razor Rocks (twice), and it was a full minute faster than in my 22-minute speedrun. So, more like 13+ seconds per day. And, obviously, it's influenced by how much stuff you have going on in your park. (Tying those 2 together, here's a little nugget for you: RCT1 doesn't show the day, only the month, but I caught Park Value updating on the same frame as the change in month. Coincidence? Could update 32 times a month, idk.)

Thus, the variable speed of the game is a factor at play in every scenario in every speedrun category.

The Windows compatibility mode you choose might affect it. Not that anyone would, but if you experiment, be sure to have save files ready to quickly re-unlock all the scenarios.

#2. Scenario Completion checks are performed about every 14 seconds, starting the moment you first open the scenario.

Yeah, pretty darn simple once you've ruled out what it's not based on.

#3. EIN (Excitement, Intensity, Nausea) calculation has the following properties:

By "Ride ID" (good luck finding that anywhere on the internet) Marcel was referring to the order of rides based primarily on what was built first. In Finish-5 scenarios, this is simple: Roller Coaster 1, Roller Coaster 2, etc. They receive EIN calculations in that order. Elsewhere, if you delete "Roller Coaster 1" and build a new "Roller Coaster 1", the new one usurps its place as first in line. Renaming does nothing.

The calculations "take" anywhere from 0.2 seconds for just a couple of station tiles to 2 seconds for an average-sized coaster, and beyond. A 1.5 second interval is average for a Finish-5 coaster. If you finish developing your coaster design and measure the EIN interval, you can expect it to be the same in any playthrough, +/- 1 frame. (However, on Dusty Desert I painstakingly duplicated the terrain around Rollercoaster 1 & 2 to build copies on the other side of the map--and got drastically different EIN intervals.)

The last coaster's EIN update is followed by an approximately 6.8 second refractory period where no EIN calculation is being done at all. Then, the cycle begins again with the first ride/coaster. Even if no changes are made to the rides or park, it keeps calculating them in this way, taking the same amount of time. 6.8 seconds off, 9 seconds to calculate 5 EINs, 6.8s off, etc.

Calculations are performed for rides which are in testing mode or open. Closed rides are not included in the calculation cycle. They are thrown into the mix as soon you hit test; it doesn't wait for them to complete a circuit.

Normally a ride should complete its first circuit before its calculation interval starts to receive the EIN. Sometimes a ride can arrive in the middle of its interval and get its EIN in half the time.

As for when the cycle starts, good luck finding correlation with anything. You're better off trying blindly over and over hoping the EIN lines up perfectly than running the numbers back to try to work out when you should start testing each ride.

#4. Pausing the game pauses everything: Park Value calculation cycles, Scenario Completion checks, EIN rendering.

For the complete 5 coaster scenarios, stop the clock at last player action (e.g. hitting yellow or green light on 5th coaster or last scenery placement).

Reason: the time the game takes to register scenario completion can vary by more than 20 seconds. Who wants to be at the mercy of RNG to that extent?

Here's an (actual) example in which we wait on a 5th coaster (Steel Wild Mouse) with a ride time of 45 seconds. (Other 4 coasters already tested.) Playthrough 1: All coasters in test mode by 2m30s. Ratings display after 48 seconds. Scenario completes 2 seconds later. Final time: 3m20s Playthrough 2: All coasters in test mode by 2m20s. Ratings display after 54 seconds. Scenario completes 7 seconds later. Final time: 3m21s

I don't know how or how often the game does the calculations. It's chaos.

This suggestion may seem to cater specifically to my personal playstyle by punishing scenery placement after putting all coasters into operation. i.e. normal player reaches target Excitement for the coaster with a 20 second build time and 5 seconds of scenery placement, and I with a 25 second build time and 0 seconds of scenery placement. Currently, that gives them a 5 second advantage. Under the proposed change, we're equal. More importantly, scenery spammers are also at the mercy of the RNG, and may feel compelled to keep redoing the whole scenario until they do it well AND the game registers the completion quickly. Me not using scenery was an unnecessary flex, but it's not like it's terribly unreasonable to measure the amount of time it took the player to perform all the actions necessary to complete the scenario. "Last Player Action" would be similar to an Open RCT2 FF run (without going through the rigmarole of fast-forwarding), though there are significant differences in how coasters function between the two games.

Another, slightly more complicated alternative, which keeps the scenery spammer advantage: Stop the clock when last coaster's train arrives back at the station and restraints come up--when the bottom stats show up, and E.I.N. are still pending. That's basically scenario completion minus the random interval, so it wouldn't influence a change in playstyle. Cons: Requires the windows to be open to the stat tab or the station to be visible (or stations, in the case of Dusty Desert, which are too far apart for this).