2048 kickstart for use on i.e. http://gabrielecirulli.github.io/2048/ (only tested in Chrome)

2048_pattern_tester.js

// Sequence of keys to press
var sequence = "luuluuruuruuluuluuruuruu"; // averaging 4000
var stalledKey = "d";

// How many iterations you want to try?
var iterations = 100;

// Stop trying at minimum score of
var haltat = 5000;

// Some weird code
var map = {
    "l":    37,
    "u":    38,
    "r":    39,
    "d":    40
};

// Reset the game
var e = document.createEvent("Events");
e.initEvent("click", true, true);
document.querySelector('.retry-button').dispatchEvent(e);

// Emulate key press function
function fireKey(direction)
{
    var key = map[direction];
    var e = document.createEvent("Events");
    e.initEvent("keydown", true, true);
    e.which = key;
    document.getElementsByTagName('body')[0].dispatchEvent(e);
}

// Init vars
sequence = sequence.split("");
var index = 0;
var scores = [];
var left = iterations;
var running = true;
var score;
var stalled = [];

// Is the given score the same as the current one, press stalled key
var checkstalled = function(current_score) {
    return function() {
        if (current_score == score) {
            console.log("stalled?");
            fireKey(stalledKey);                
            for (var i = 0, len = stalled.length; i < len; i++) {
                if (stalled[i]) {
                    clearTimeout(stalled[i]);
                    stalled[i] = null;
                }
            }    
        }
    };
};

// Do the loop
clearInterval(loop);
var loop = setInterval(function() {
    
    if (index >= sequence.length) index = 0;
    
    fireKey(sequence[index]);    
    score = parseInt(document.querySelector('.score-container').textContent, 10);
    
    if (score >= haltat) {
        clearInterval(loop);
        return;
    }
    
    if (document.querySelector(".game-message.game-over")) {                 
        if (!left && running) {
            console.log('best score ' + Math.max.apply(Math, scores) + ", average " + (scores.reduce(function(a, b) { return a + b }) / scores.length) );
            running = false;
        } else if (running) {            
            scores.push(score);
            console.log("score " + score + ", average " + (scores.reduce(function(a, b) { return a + b }) / scores.length) );            
            var e = document.createEvent("Events");
            e.initEvent("click", true, true);
            document.querySelector('.retry-button').dispatchEvent(e);
            left--;
        }
    } else if (!running) {
        left = iterations;  
        running = true;
    } else {
        stalled.push(setTimeout(checkstalled(score), 250));
    }
    
    index++;
}, 1);

console.log("started");

2048_pattern_tester.min.js

function fireKey(a){var b=map[a],c=document.createEvent("Events");c.initEvent("keydown",!0,!0),c.which=b,document.getElementsByTagName("body")[0].dispatchEvent(c)}var sequence="luuluuruuruuluuluuruuruu",stalledKey="d",iterations=100,haltat=5e3,map={l:37,u:38,r:39,d:40},e=document.createEvent("Events");e.initEvent("click",!0,!0),document.querySelector(".retry-button").dispatchEvent(e),sequence=sequence.split("");var index=0,scores=[],left=iterations,running=!0,score,stalled=[],checkstalled=function(a){return function(){if(a==score){console.log("stalled?"),fireKey(stalledKey);for(var b=0,c=stalled.length;c>b;b++)stalled[b]&&(clearTimeout(stalled[b]),stalled[b]=null)}}};clearInterval(loop);var loop=setInterval(function(){if(index>=sequence.length&&(index=0),fireKey(sequence[index]),score=parseInt(document.querySelector(".score-container").textContent,10),score>=haltat)return clearInterval(loop),void 0;if(document.querySelector(".game-message.game-over")){if(!left&&running)console.log("best score "+Math.max.apply(Math,scores)+", average "+scores.reduce(function(a,b){return a+b})/scores.length),running=!1;else if(running){scores.push(score),console.log("score "+score+", average "+scores.reduce(function(a,b){return a+b})/scores.length);var a=document.createEvent("Events");a.initEvent("click",!0,!0),document.querySelector(".retry-button").dispatchEvent(a),left--}}else running?stalled.push(setTimeout(checkstalled(score),250)):(left=iterations,running=!0);index++},1);console.log("started");