Late-game BTD6 and They Are Billions recordings were 71–85% repeated frames. A normal Vampire Survivors run was 5%; extreme builds hit 99%. OBS reported zero dropped frames for all of them, because repeats are not drops (why).
The measurements
| Game and footage | Repeated frames | Real motion left in 30 s |
|---|---|---|
| BTD6, round 268 (lBankedl Mr P) | 638 of 901 (71%) | 8.8 s |
| BTD6, round 400+ (Dave) | 159 of 208 (76%) | 1.6 s |
| BTD6, boss tournament (More Mehalic) | 1,340 of 1,800 (74%) + 3 menu visits | 3.25 s |
| They Are Billions, 800% Survival, Map 4 (KenseiTV) | 84% | 56 of 900 frames |
| They Are Billions, Campaign, Apocalypse 800% (indysc2) | 79% | 96 of 900 frames |
| They Are Billions, Final mission (KenseiTV) | 85% | 135 of 900 frames |
| Vampire Survivors, normal late run | 5% | almost all of it |
| Vampire Survivors, limit-break run with webcam | 12–25% | most of it |
| Vampire Survivors, “less than 1 fps” build | 39–99% | as little as 0.3 s |
Sources and method for each row are on the game pages: BTD6 late-round lag, They Are Billions final waves, Vampire Survivors late runs, and the validation table on the LagCut page.
What the numbers mean
- The games are CPU-bound, not the recorder. BTD6 and They Are Billions simulate every unit every tick on one thread; when that falls behind, the game draws fewer frames and the recorder repeats the last one (does BTD6 use the CPU or GPU).
- Speeding up doesn't help. At 3× a 74%-frozen clip is still 74% frozen, just faster (speeding up BTD6 footage).
- OBS settings can't fix it. They can stop OBS adding its own stutter (the three OBS stats), but the game's stalls are real and land in the file.
- Removing the repeats works. Cutting the repeated frames leaves continuous motion at the pace the game really ran: 8.8 seconds of real BTD6 out of 30, played back smoothly. LagCut does that in the browser for BTD6 and They Are Billions; ffmpeg mpdecimate does it for anything else.
Measure your own clip
Step through a laggy stretch frame by frame and count how many presses it takes for the game clock to change. Five presses per change at 60 fps means four in five frames are repeats, which is 80%. Or drop the clip into LagCut and read the count off the scan.
Questions people ask
What percentage of a laggy BTD6 recording is repeated frames?
In our three late-game samples, 71–76% of recorded frames were exact repeats of the previous frame.
Why does OBS say 0 dropped frames if most frames are repeats?
Because OBS wrote a frame on every tick; it just wrote the same one when the game hadn't drawn a new one. Repeats are not drops.
Can I remove the repeated frames?
Yes. LagCut does it in the browser for BTD6 and They Are Billions; ffmpeg's mpdecimate filter works for any game.