Unexpected coin toss probability

Main.java

import java.util.Random;

/*
  If Alice tosses a coin until she sees a head followed by a tail, and Bob tosses a coin until he
  sees two heads in a row, then on average, Alice will require four tosses while Bob will require
  six tosses (try this at home!), even though head-tail and head-head have an equal chance of
  appearing after two coin tosses.

  https://www.quantamagazine.org/20160313-mathematicians-discover-prime-conspiracy/
 */
public class Main {
  public static final int NUM_SIMULATIONS = 100000;
  public static final boolean HEAD = true;
  public static final boolean TAIL = false;

  private static final Random rand = new Random();

  public static void main(String[] args) {
    long totalAlice = 0;
    long totalBob = 0;

    for (int i = 0; i < NUM_SIMULATIONS; i++) {
      totalAlice += simulateUntil(HEAD, TAIL);
      totalBob += simulateUntil(HEAD, HEAD);
    }

    System.out.println("Average for Alice = " + ((double) totalAlice / NUM_SIMULATIONS));
    System.out.println("Average for Bob = " + ((double) totalBob / NUM_SIMULATIONS));
  }

  private static int simulateUntil(boolean toss1, boolean toss2) {
    int numTosses = 2;
    boolean prev = rand.nextBoolean();
    boolean cur = rand.nextBoolean();

    while (!(prev == toss1 && cur == toss2)) {
      prev = cur;
      cur = rand.nextBoolean();
      numTosses++;
    }

    return numTosses;
  }
}