Stream quality you want
720p · 60 fps
1080p · 60 fps
1440p · 120 fps
4K · 120 fps
Your download speed
Others using the connection (video calls, other streams)
Ping to the game server
How your device connects
Cable
Wi-Fi
Bandwidth: spare vs needed
Delay: total vs 40 ms and 80 ms lines
Needs per quality tier follow NVIDIA's published GeForce NOW figures. The +12 ms for Wi-Fi is an illustrative guess; real Wi-Fi varies a lot.