Do players change pace as a tactic?


and usually use most of the rest of the clock in the rest of the game in a well matched game
and if my opponent is taking more time than previously then maybe i got him stumped; it rarely happens for me but, dang, it's a nice luxury to get ahead on the clock for once
i have people abandon or worse- milk out 25minutes of clock when they blunder and i will wait them out; this usually happens when my ipad battery is at 2% and goes dead then i have to frantically reconnect on iphone to not autoresign myself but i think you are talking about something else
what time control are you talking about?

I think deliberate slow playing to trick your opponent into thinking you're unsure of what you're doing or distracted, is a perfectly legitimate tactic.
The other day, I played the Fritz variation (a counter to the Fried Liver Attack) but I played the knight move so quickly, that my opponent thought for a long time and didn't continue his attack. Maybe he just didn't see how to continue, but maybe he smelled a rat: "he moves so quickly, he's up to something. I don't know what, but I'm not falling for it." Now I'm thinking that if I had played more slowly, perhaps my opponent would think I don't know what I'm doing and he would have fallen for the trap.
But yes, sometimes the phone rings, or the doorbell, or I need to go pee.