I have created a Library for chess game in JavaScript.

In this library i decided that game should only be over when detect checkmate or insufficient material. Game is working properly for checkmate but I need to add function for detecting insufficient material condition to draw the game.

I have a object which is updated every time when one side piece kill piece of another side.

let count = {
   W: {
       K: 1,
       Q: 1,
       P: 8,
       R: 2,
       N: 2,
       B: 2,
   },
   B:{ /* Black piece */ }
} 

So my question is how can i detect a insufficient material using above object in JavaScript.