What is a Popsplit and how can I do it (agar.io)?
Solution 1:
You popsplit by splitting twice into an enemy within range of a virus:
(sqrt(opponent's mass + your mass/4)-sqrt(opponent's mass))/pi mass distance
In other words, the opponent needs to be big enough to hit the virus after consuming one of your pieces. I'd recommend using a macro (see: ogar) and popsplitting enemies slightly larger than half your size (preferably within 8% of a difference.)
Ogar can be downloaded here.