Mahjong as a 2D Array

Messing with data structures and ways of storing a Mahjong hand. Bellow is interactive! Click (or tap) to discard :3c

Ideally I'd also love to render your hand score as well, but that's for another time!

Here's the data type used for storing a hand:

type Hand<T = number> = [
  /*        Red 5   1  2  3  4  5  6  7  8  9 */
  /* S */ [ T,      T, T, T, T, T, T, T, T, T ],
  /* P */ [ T,      T, T, T, T, T, T, T, T, T ],
  /* M */ [ T,      T, T, T, T, T, T, T, T, T ],
  /* Z */ [ null,   T, T, T, T, T, T, T],
  /*                E  S  W  N  W  G  R */
];