How an AI bot beat the world's best gamers
Last month, a bot developed by OpenAI (co-founded by Elon Musk) beat the world’s best, pro Dota 2 players. This is another milestone accomplishment in the field of artificial intelligence and machine learning and more fuel for the fire of concerns surrounding the AI debate. However, before we jump into that debate, here is some background you should understand about the technology fueling this debate.
The Evolution of Traditional Programming
A lot of what computer programming is can be simplified into three steps. First step, read in some data. Second step, do something with that data. Third step, output some result.
For example, imagine you want to fly somewhere for the weekend. You may first go to your travel app and input some dates, times, number of people traveling, airports, etc. Second, the app uses that information to search its database of available flights. Third, it returns a list of available flights for you to see.
This approach to software design has been the norm since the earliest days of programming. Artificial intelligence, in particular machine learning, has changed that approach. The first step is still the same: Read in some data. The third step is the same: Output some result.
However, with artificial intelligence technologies like machine learning, the second step, doing something with the data, is very different. In the example of finding a flight, a programmer easily can read the software code to understand the sequence of steps the computer has been programmed to do to produce the output data. If the programmer wants to change or improve the program’s behavior she can do that by writing new code or by altering the existing code. For example, if you wanted to compare the prices for available flights near the dates you have selected, a programmer can easily change several lines of code in the program to do just that. The programming code identifies every step the computer takes to arrive at its output. Said another way, the program only does what it’s specifically told to do in the code, nothing more or nothing less.
By contrast, the output of today’s most common machine learning programs is not determined by instructions written in computer code. There is no code for a programmer to read or modify when a change is desired. The output is determined by the program’s neural network.
Neural Networks in Action
What is a neural network? At the core of a neural network is a neuron. Similar to a traditional computer program, a neuron takes some input data, does a mathematical calculation on that data and then outputs some data. A typical neuron in a neural network will receive as input hundreds to thousands of numbers, typically between 0 and 1. A neuron will then multiply each number by a weight and sum the result of all the numbers. Many neurons will then convert the result into a number between 0 and 1. That result is then sent to the next neuron in sequence until the final output neuron is reach.
Here is an example of the math a typical neuron will do: If “x1, x2, x3…” represents input data and “w1, w2, w3…” represent the weights stored in the neuron, the calculation done by the neuron in a neural network looks like this: x1*w1 + x2*w2 + x3*w3 and so forth.
You can think of the calculation inside the neuron in a different way: The neuron is reading in a bunch of numbers and the weights in the neuron determine the importance, “or weight” of that input in producing the output. If the input is not important the weight for the input will be near zero and the input is not passed along to the next neuron. Therefore, the weights in a neuron effectively decided what input is valuable and what input should be ignored.
In a neural network, neurons like the one I described above are connected in parallel and in series to create a matrix of neurons. The input data to a neural network will go into hundreds or thousands of neurons in parallel, all with different weights. The output of those neurons is then sent to another layer of neurons and so forth, usually multiple layers deep. This is called a deep neural network. Another way to look at this is the neurons are grouped into a matrix of rows and columns, all interconnected. The final layer of the neural network is the output layer. Therefore, the final output of a neural network is the result of millions of calculations done by the neurons of that network.
When a programmer creates a neural network in software, the weights for each neuron are initially just random numbers. In other words, the weights arbitrarily decide to either diminish, increase or leave the input data alone, and output from the network is random. However, through a process called training, the weights move from randomly assigned values to values that can produce very useful outputs.
Training is both a time consuming and complicated mathematical process. However, it is much like training you and I would do to get better at something. For example, let’s say I wanted to learn how to shoot and arrow with a bow. I might pick up the bow and arrow, point it at the target, pull back the string and release. In my case, I know the arrow would miss the target. Therefore, I would try again and again making corrections to my aim based on on how far and which direction I was off from the target.
During the training process for a neural network, the weights in each of the neurons are changed slightly to improve the output, or “aim.” The most common approach for making those changes is called backpropagation. Backpropagation is a mathematical approach for applying corrections to every weight in every neuron of the network. During training, input is fed into the network and output is generated. The output is compared to the desired target and the difference between the output and the target is the error. Using the error, backpropagation makes changes to the weights in each neuron to reduce the error. If all goes well during training and backpropagation, the output error diminishes until it reaches expert or better than expert level.
AI vs Humans
In the case of the OpenAI Dota bot that recently beat the world’s best Dota 2 player, the outputs, which were a sequence of steps, strategies and decisions, went from random moves to moves that were so good the bot was able to easily defeat the best pro players in the world. The critical information that enabled the bot to win its matches was stored in the weights of the neurons and the neural network architecture itself.
A good question at this point is to ask if a programmer looking at the Dota 2 bot’s neural network could understand the steps taken by the bot to beat the human player. The answer is no. A programmer can see areas of the neural network that influence an output but it is not possible to explain why the bot took specific steps to formulate its moves and strategies. All the programmer would see is a huge matrix of weights that would be quite overwhelming to interpret.
Another good question to ask is whether or not a program written traditionally by a programmer with step by step instructions could beat the best Dota 2 player. The answer is no. Step by step programs where the programmer specifically instructs the computer to do something would easily be defeated by a professional player. However, a neural network can learn from training things that a programmer would never have the knowledge to program, store that learning in its neurons and use that learning to do things like defeat a human pro.
What makes the Dota 2 bot special is that it learned to beat the best pro players by playing against itself whereas most machine learning programs learn from training on data given to it by a programmer. In machine learning, good training data is like gold. It’s scarce and valuable. (note: This is one reason why Google and other big tech companies want to collect so much data.) Data is used to train neural networks to do useful things like recognizing people and places in your pictures or recognizing your voice from others in your family. OpenAI built a bot that learned almost entirely by playing against itself with the exception of some coaching provided by the OpenAI team. OpenAI has shown clearly that learning can occur without having tons of training data. It’s a little like being able to make gold.
Does the development of the OpenAI dota bot mean bots can now decide to train against themselves and become super bots? No. But it does say that humans can now program two bots to train against each other to become superbots. The key enabler being us. It’s anyone’s guess what type of bot can be imagined and developed in this way, useful or harmful. Obviously to most, a gaming superbot seems pretty innocuous, except of course to the gamer who may unexpectedly run into one during a match. However, it’s not hard to imagine super bots that are not so harmless. Or, perhaps you can just imagine a time when someone trains a bot to play football against itself until the bot becomes better at calling plays and strategy than every coach in the NFL. What happens then? The answer is disruption. Are you ready for it?
AKF Partners recommends that boards and executives direct their teams to identify sources of innovation and patterns of disruption that AI techniques may represent within their respective markets Walmart is already working on facial recognition technology in their stores to determine whether or not shoppers are satisfied at checkout. Will this give them a potential advantage over Amazon? How can machine learning and AI help you prevent fraud in your payment systems or the use of your commerce system to launder money?
AKF is prepared to help answer that question and others you may be facing. We will help you craft your AI strategy, sort through the hype, help you find the opportunities, and identify the potential threats of AI technology to your business.