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The Synergy of Human-Machine Teams in Chess

Exploring how humans and machines can collaborate effectively in chess.

David Shoresh, Yonatan Loewenstein

― 9 min read


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Table of Contents

Collective Intelligence refers to the idea that a group can outperform individual members. This concept is essential in various settings, from businesses to sports teams. Interestingly, it suggests that teams can achieve much more than single players, like a pizza made by five chefs is likely tastier than one chef's attempt.

When we mix humans and machines into a team, the situation can get a bit tricky. Machines, especially advanced ones like deep neural networks, often work in ways that humans can't fully understand. Imagine trying to take directions from a GPS that talks in riddles. That's how it feels when we collaborate with certain AI systems!

The Challenge of Human-Machine Teams

Human teams often thrive by communicating effectively and finding out each member's strengths. However, machines usually don't chat or express their strengths in relatable terms. Instead, they rely on complex algorithms that can be hard to interpret. This is where the struggle begins.

For instance, in some chess tournaments in the early 2000s, human players partnered with machines to form teams known as "centaurs." These teams were quite successful, even outshining the best human players and machines on their own. Centaurs reported that knowing their machine's strengths helped them perform better. They recognized how to leverage each other's capabilities, akin to a chef knowing when to handle the dough and let a bread machine do the kneading.

Team Composition

In the world of chess, we had two types of machines in our latest experiments. One was a human-like model trained using actual human game data, and the other was a model that played against itself to learn how to play better. Together, they formed a team that could compete against traditional chess engines.

The human-like model, which we'll call Maia, played with another model, named Leela. Leela didn't learn from humans but gained experience from countless games against itself. They teamed up against a popular chess engine called Stockfish, which uses a different evaluation method to make decisions.

The Mixture of Experts Approach

To figure out how to best use these two players, we employed a method called a "Mixture of Experts" (MoE). You can think of this as a team of specialists in a meeting, where each expert has a say based on what they're good at. The manager of this team selects which recommendation to follow, based on the situation. Every time they faced a decision on the chessboard, they would either agree on a move or let the manager choose.

Setting Up the Experiment

To study how well this human-machine team could work together, we needed to set clear rules for team play. If Maia and Leela agreed on the best move, they would execute it. If they disagreed, a manager would decide which move to take. This mimics how humans sometimes have to make tough decisions after discussing their options.

To assess the team's performance, we looked at the winning, drawing, and losing outcomes against their opponent. This gave us a clear understanding of how effective their partnership was.

Exploring Relative Advantages

A big part of our study focused on finding out how team members could identify each other’s strengths. This is especially important when one player is a high-performing machine and the other is a human-like player.

In traditional business settings, some argue that it's essential for managers to be experts in what their team does. An expert manager might know a lot about chess and make very calculated decisions, but that doesn’t always lead to better results. This is similar to how a chef might know a lot about cooking but can’t always create the perfect dish without working with the right ingredients.

The Role of Domain Knowledge

To tackle these questions, we looked at various chess tournaments where human-machine teams were formed. In these events, players would take the role of centaurs, combining their efforts to analyze positions on the chessboard.

While we thought that strong subject matter knowledge could help identify relative advantages, we found that it wasn’t always necessary. Just like a manager might excel at knowing how to motivate their team rather than being the best player themselves, it seems that understanding the strengths of each player may be more beneficial than simply having extensive knowledge of the game.

Training a Network

To further investigate, we trained a separate network, which didn’t know anything about chess. This network learned to recognize the advantages of its team members just through experience. Surprisingly, it outperformed the chess expert, showing that sometimes a fresh perspective could be more valuable than traditional expertise.

To see how well the teams would perform in various situations, we put together different versions of Maia and Leela against stronger versions of Stockfish. We assessed how well they did in both symmetric (where players are of equal strength) and asymmetric (where one player is notably stronger) settings.

Results from Symmetric Teams

When we tested the symmetric teams, we found that they did indeed achieve better results than each player could on their own. This shows that even with machines and humans, there was potential synergy.

The expert manager, representing a strong chess engine, also performed well, suggesting that having some expertise could help. However, the increasing depth of this expertise didn't translate to a significant spike in performance. The so-called "curse of knowledge" might play a role here, as sometimes too much expertise could cloud judgment.

Results from Asymmetric Teams

When we moved on to test asymmetric teams with varying strengths, the results were less favorable. While the RL manager did excel in moderately asymmetric situations, it fell short in cases with larger disparities. Yet even in these challenging scenarios, some potential synergy remained.

As the asymmetry grew, the ability to identify advantages among team members became increasingly difficult. This suggests that while there may be high potential for synergy, recognizing the valuable contributions of team members is not as straightforward as it seems.

Discovering Team Member Choices

We also investigated how often the managers would choose Maia or Leela during their decision-making. The oracle manager, which represented an ideal scenario, tended to favor certain players based on the situation. Interestingly, it appeared that there were only a few crucial decisions where the inferior player could offer significant contributions.

This finding underscores the challenge in human-machine collaborations. Identifying those key moments is important, yet it may not always be easy, especially as team configurations become more complex.

Delving into the RL Manager

Our RL manager, which was specifically trained without any prior knowledge of chess, managed to learn something about the game while recognizing the strengths of its teammates. To see if this network possessed any real understanding of chess, we looked at how it focused on different pieces and positions on the board.

When we assessed its attention scores, we found that it was more likely to focus on pieces rather than empty squares. It even demonstrated a preference for attacked pieces over those that weren’t, indicating an implicit understanding of chess dynamics.

The Importance of Understanding

As we dug deeper into the RL manager's functioning, we tested whether it implicitly learned to predict its team's moves. We found no substantial evidence that it could predict recommendations from Maia or Leela. This suggests that the RL manager could distinguish the strengths of its teammates without a detailed understanding of each move.

In the grand scheme of things, this points towards the idea that recognizing relative advantages can be done with less comprehensive domain knowledge.

Exploring Human Understandable Features

To make sense of how the RL manager distinguished among its teammates, we developed a set of human-friendly features based on chess strategies. These included elements like the count of moves made, the pieces’ material points, and the number of attacks available.

When we analyzed how these features affected the team’s performance, we found no clear, strong connections. It appeared that the RL manager didn’t utilize easily interpretable features for decision-making. This underlines a key point: sometimes, understanding complex situations in simpler terms isn't the best approach.

Maia's Human Resemblance

Throughout our work, we assumed that Maia represented human-like behavior well enough. She matched human move tendencies and displayed common chess biases, but deploying her in the setting of our team potentially distorted her human-like qualities.

To check this, we examined various biases found in human chess, such as preferences for aggressive moves or central positioning. Overall, Maia seemed to share these biases, reinforcing the idea that she can act like a human player in many respects.

Related Studies

The themes of collective intelligence, human-machine teams, and the role of diversity in teams have been explored extensively. The benefits of diversity have been shown in both human and machine settings, suggesting that mixing different strengths can enhance overall team performance.

However, not every team achieves synergy, especially when communication breaks down. In human teams, effective communication is crucial to success, and this can be even more complicated when machines are involved, as they may not communicate in straightforward ways.

Conclusions

In summary, we explored the dynamics of human-machine teams, particularly in the context of chess. Through various experiments and analyses, we found that there is significant potential for these teams to work together effectively, even when the team members vary greatly in skill levels.

We learned that identifying relative advantages among team members is key to achieving synergy, but this task can be complex. The right balance of domain knowledge and understanding of each player’s strengths can lead to better decision-making outcomes.

Ultimately, whether in chess or other fields, human-machine teams are likely to become increasingly common. Finding ways to help these teams collaborate effectively will be crucial in the evolving landscape of technology and work. And remember, like making pizza, it's all about knowing how to mix the right ingredients for success!

Original Source

Title: Modeling the Centaur: Human-Machine Synergy in Sequential Decision Making

Abstract: The field of collective intelligence studies how teams can achieve better results than any of the team members alone. The special case of human-machine teams carries unique challenges in this regard. For example, human teams often achieve synergy by communicating to discover their relative advantages, which is not an option if the team partner is an unexplainable deep neural network. Between 2005-2008 a set of "freestyle" chess tournaments were held, in which human-machine teams known as "centaurs", outperformed the best humans and best machines alone. Centaur players reported that they identified relative advantages between themselves and their chess program, even though the program was superhuman. Inspired by this and leveraging recent open-source models, we study human-machine like teams in chess. A human behavioral clone ("Maia") and a pure self-play RL-trained chess engine ("Leela") were composed into a team using a Mixture of Experts (MoE) architecture. By directing our research question at the selection mechanism of the MoE, we could isolate the issue of extracting relative advantages without knowledge sharing. We show that in principle, there is high potential for synergy between human and machine in a complex sequential decision environment such as chess. Furthermore, we show that an expert can identify only a small part of these relative advantages, and that the contribution of its subject matter expertise in doing so saturates quickly. This is probably due to the "curse of knowledge" phenomenon. We also train a network to recognize relative advantages using reinforcement learning, without chess expertise, and it outdoes the expert. Our experiments are repeated in asymmetric teams, in which identifying relative advantages is more challenging. Our findings contribute to the study of collective intelligence and human-centric AI.

Authors: David Shoresh, Yonatan Loewenstein

Last Update: Dec 24, 2024

Language: English

Source URL: https://arxiv.org/abs/2412.18593

Source PDF: https://arxiv.org/pdf/2412.18593

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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