momthy_floor.js

var iterations = 100000000;

var stats = {
  win: 0,
  loose: 0
}

function generatePrises() {
  var initial = [0, 0, 0];
  initial[Math.floor(Math.random() * 3)] = 1;
  return initial;
}

function chooseRandom() {
  return Math.floor(Math.random() * 3);
}

for (i = 0; i<=iterations; i++) {
  var prises = generatePrises();
  var choose = chooseRandom();
  if (prises[choose] == 1) {
    stats.win++;
  } else {
    stats.loose++;
  }
}


console.log(stats, stats.win / iterations * 100);

momthy_round.js

var iterations = 100000000;

var stats = {
  win: 0,
  loose: 0
}

function generatePrises() {
  var initial = [0, 0, 0];
  initial[Math.round(Math.random() * 2)] = 1;
  return initial;
}

function chooseRandom() {
  return Math.round(Math.random() * 2);
}

for (i = 0; i<=iterations; i++) {
  var prises = generatePrises();
  var choose = chooseRandom();
  if (prises[choose] == 1) {
    stats.win++;
  } else {
    stats.loose++;
  }
}


console.log(stats, stats.win / iterations * 100);