Simulation Code

package test;

import java.io.IOException;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;

import net.minecraft.enchantment.Enchantment;
import net.minecraft.enchantment.EnchantmentHelper;
import net.minecraft.init.Bootstrap;
import net.minecraft.init.Enchantments;
import net.minecraft.init.Items;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagList;

public class TestMain {

    public static void main(String[] args) throws IOException {
        Bootstrap.register();

        final ItemStack HELMET = new ItemStack(Items.DIAMOND_HELMET);
        Random rand = new Random();
        final float clampedAdditionalDifficulty = 1;
        NumberFormat numberFormat = NumberFormat.getNumberInstance();

        Map<List<Enchantment>, Integer> counts = new HashMap<>();

        for (int i = 0; i < 1_000_000_000; i++) {
            if (i % 10000 == 0)
                System.out.println(numberFormat.format(i));
            ItemStack helmet = HELMET.copy();
            helmet = EnchantmentHelper.addRandomEnchantment(rand, helmet, (int) (5 + clampedAdditionalDifficulty * rand.nextInt(18)), false);
            if (rand.nextFloat() < 0.5f * clampedAdditionalDifficulty) {
                helmet = EnchantmentHelper.addRandomEnchantment(rand, helmet, (int) (5 + clampedAdditionalDifficulty * rand.nextInt(18)), false);
            }

            List<Enchantment> enchantments = new ArrayList<>();
            NBTTagList list = helmet.getTagCompound().getTagList("ench", 10);
            for (int j = 0; j < list.tagCount(); j++) {
                Enchantment ench = Enchantment.getEnchantmentByID(list.getCompoundTagAt(j).getShort("id"));
                int level = list.getCompoundTagAt(j).getShort("lvl");
                if ((ench == Enchantments.PROTECTION || ench == Enchantments.FIRE_PROTECTION) && level == 3) {
                    enchantments.add(ench);
                } else if ((ench == Enchantments.BLAST_PROTECTION || ench == Enchantments.PROJECTILE_PROTECTION) && level == 4) {
                    enchantments.add(ench);
                }
            }
            enchantments.sort(Comparator.comparing(Enchantment::getEnchantmentID));
            counts.put(enchantments, counts.getOrDefault(enchantments, 0) + 1);
        }

        counts.forEach((enchantments, count) -> {
            System.out.println("==============");
            enchantments.forEach(ench -> System.out.println(Enchantment.REGISTRY.getNameForObject(ench)));
            System.out.println(numberFormat.format(count));
        });
    }

}