Why YSK?

Because a lot of older games require immediate response from the controller (think jumping over pits).

Each TV is different, and may or may not have a game mode. For the longest time, I thought my lag was because of my Raspberry PI (model 4, 4gb). Turns out that turning on the game mode/game optimizer was all I needed. I also added a link to a post that has suggestions for Retroarch changes that can decrease input lag. Relavant content from post:

  1. Set max swapchain to as low as possible, I think 1 and 2 run pretty similarly.
  2. Turn on hard gpu sync and set it to 0
  3. Set frame delay as high as you can go before you get stuttering. On the pi 1, I can go to about 8 with NES core and 4 with SNES. On Pi 3 you can probably go higher, but systems with higher graphics like N64 and PSX won’t let you go as high before you run into problems.

And:

(when asked where the settings are) You need to access the retroarch rgui menu while you are in a game. You can do this by pressing X button and select at the same time. Once you get to the rgui menu, you want to click on settings, then video.