Snakes & Snakes RM

function rollDice(){
    $roll =  random_int(1,6);
    //echo("Rolled: " . $roll . "\n");
    return $roll;
}

function runGame(){
    $snakes = array(
        14 => 4,
        17 => 7,
        31 => 9,
        38 => 20,
        54 => 34,
        59 => 40,
        62 => 19,
        64 => 60,
        67 => 51,
        81 => 63,
        84 => 28,
        91 => 71,
        93 => 73,
        95 => 75,
        99 => 78
    );

    $moves = 0;
    $fallen = 0;
    $pos = 0;
    for($pos = 0; $pos < 100; $pos += 0){
        //Roll 6 to start
        if($pos == 0){
            if($moves == 0){
                if(rollDice() != 6 && rollDice() != 6 && rollDice() != 6){
                    $moves ++;
                    continue;
                }
            }else{
                if(rollDice() != 6){
                    $moves ++;
                    continue;
                }
            }
        }
        $roll = rollDice();
        $pos += $roll;
        //Hit 100 exactly, go back when overshooting
        if($pos > 100){
            //echo "From $pos to " . 100 - ($pos - 100);
            $pos = 100 - ($pos-100);
        }
        $moves ++;
        //Fall down the snake ladder
        if( array_key_exists($pos, $snakes) ){
            $moveTo = $snakes[$pos];
            //echo "Oh no! Falling from $pos to $moveTo!\n";
            $pos = $moveTo;
            $fallen++;
        }
        if($roll == 6){
            $moves --;
            continue;
        }
    }
    //echo "YOU WON! Turns: $moves and fallen $fallen times.";
    return [$moves, $fallen];
}

$sampleSize = 100000;

$totalMoves = [];
$totalFalls = [];
for($i = 0;$i < $sampleSize;$i ++){
    $game = runGame();
    $totalMoves[] = $game[0];
    $totalFalls[] = $game[1];
}
$averageMoves = array_sum($totalMoves) / $sampleSize;
$averageFalls = array_sum($totalFalls) / $sampleSize;

$maxMoves = max($totalMoves);
$maxFalls = max($totalFalls);

$minMoves = min($totalMoves);
$minFalls = min($totalFalls);

echo "Average turns: $averageMoves \n";
echo "Average falls: $averageFalls \n";
echo "Game with most turns: $maxMoves \n";
echo "Game with most falls: $maxFalls \n";
echo "Game with least turns: $minMoves \n";
echo "Game with least falls: $minFalls \n";