Maybe he is talking about something like this:
Back when I was sub-28, I did F2L algs at 5~ tps (I did 5-6 turns every tick of the clock), but I paused so much due to bad lookahead that when I computed my average tps, it panned out as 2.6 tps.
Basically, I was doing 5 tps, but due to pausing too much in between pairs, the computation yielded 2-3 tps (ugh).
Anyway, TS is using a metronome so it'd probably pretty accurate for him.
If you want to have an accurate measure of your performance, try using a
metronome.
It's good training for F2L lookahead too, as well as smooth solving.
In that link I gave you above, try setting it to 72 bpm first.
For each "tick" of the metronome, do only one move.
But you are not allowed to pause to think, if you miss a tick, you have to start over.
You are also not allowed to "stall" by doing useless moves during a tick just so you can think, as well as doing unplanned moves, such as a random U turn.
Solve the entire F2L this way
(well, except for the last pair, do that at full speed).
This will train your lookahead, and also make your solves smoother.
160 bpm is a good target, you should be sub-20 if you manage that, unless you are doing excessive moves for your F2L (your cross+F2L move count should be barely less than 40...I think) or have bad LL.
---
Also, you can compute your TPS from a metronome solve by taking the metronome BPM setting and dividing it by 60.