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Praxis Studio Self-Play Reinforcement Learning & MCTS

Reinforcement Learning · Monte Carlo Tree Search · AlphaZero Architecture

Teaching a machine to think through chess. An experimental research environment exploring how AI systems learn through self-play, neural evaluation and search.

Surreal chess pieces suspended over a warped board — search, strategy, and self-play

Surreal chess pieces suspended over a warped board — search, strategy, and self-play

Teaching a machine to think through chess.

Praxis Studio is an experimental research environment exploring how an AI system can learn to play chess through self-play, neural evaluation and search.

The project takes inspiration from the AlphaGo Zero and AlphaZero research programmes, but treats the system as a research instrument rather than simply a chess engine. The goal is to make the learning process visible: what the model believes, where it searches, how those beliefs change, and how repeated self-play gradually produces stronger decisions.

Instead of encoding thousands of chess heuristics by hand, the system starts with the rules of the game and learns through repeated interaction with itself. A neural network produces two signals from a board position:

  • Policy (P) — which moves appear promising.
  • Value (v) — how favourable the current position appears.

Monte Carlo Tree Search then uses these predictions to decide where to spend computational effort. Promising moves receive more simulations, deeper branches are explored, and the resulting search statistics become training targets for the next iteration.

Launch Praxis Game Environment

Live interactive self-play and evaluation engine · praxis.knolink.co.za

01 · The Learning Architecture

Search tree topology

MCTS Multi-Path Expansion & Pruning

|
Depth:
Root · s₀Ply 1 · Light searchPly 2 · Medium searchPly 3 · Deep searchPly 4 · Decision horizons₀ (Initial)1600 visits · P: 1.001. e4940 visits · P: 0.421. d4450 visits · P: 0.311. Nf3160 visits · P: 0.151. c450 visits · P: 0.081... c5580 visits · P: 0.391... e5280 visits · P: 0.341... e680 visits · P: 0.121... d5310 visits · P: 0.521... Nf6140 visits · P: 0.382. Nf3440 visits · P: 0.682. Nc3110 visits · P: 0.182. c330 visits · P: 0.082... d6310 visits · P: 0.482... Nc690 visits · P: 0.322... e640 visits · P: 0.16
Selected state

s₀ (Initial)

Search depth

Ply 0

Prior P(s,a)

1.00

Visit count N

1600

Expected value Q

+0.12

Search behaviour & computationLight search

Initial root position evaluated by neural network f_θ(s₀). Generates baseline prior distribution across all legal candidate actions.

Clicking any candidate move above reveals its accumulated visits and neural valuation. PUCT continuously balances high-probability exploration with deep simulation down lines where expected win-rate Q(s,a) remains elevated.

The search is the experiment

One of the central ideas behind Praxis is that the model should not simply output a move.
It should reveal how it arrived there.

The interface exposes the search tree as it expands across the board, showing candidate moves, visit counts, policy probabilities, value estimates and the changing distribution of the search.

A move such as e4 is therefore not just a prediction. It becomes the visible result of thousands of competing possibilities being explored, evaluated and discarded.

PUCT selection rule

Score(s, a) = Q(s,a) + c_puct · P(s,a) · (√N(s) / (1 + N(s,a)))

Where Q(s,a) is accumulated action value, P(s,a) is the neural prior, N(s) is total state visits, and c_puct controls exploration.

The important idea is the tension between what the network already believes and what the search still needs to investigate. High-value moves attract search because they look good. High-prior but under-explored moves receive an exploration bonus. Over many simulations, the tree concentrates computation around the lines that appear most informative.

From search tree to learning signal

The search does more than select a move. It produces a richer target than the network's original prediction.

The policy head may initially assign probability across many legal moves. MCTS then transforms that uncertain distribution into a search-informed policy based on repeated exploration.

board position (s) → search policy (π) → game outcome (z)

The network is subsequently optimized to become better at predicting both:

  • 1. The network guides the search.
  • 2. The search generates experience.
  • 3. Experience improves the network.
  • 4. The improved network guides a better search.

This self-improvement loop is the foundational breakthrough demonstrated in AlphaGo Zero and AlphaZero.

What the studio makes visible

Praxis Studio is designed around the telemetry of learning. Rather than hiding training behind a single model checkpoint, the interface exposes the system's internal process:

Self-PlayWatch the agent play against itself and generate experience.
Search TreeFollow MCTS branching as it evaluates alternative futures.
Policy DistributionObserve probability density across candidate moves.
Value EvaluationTrack scalar expectation of eventual terminal outcome.
EntropyMeasure policy concentration and uncertainty.
ELO ProgressionAudit tangible strength gains across iterations.

02 · Internal Geometry

Internal representations

Praxis Latent Space Geometry

Experimental visualization of internal representation geometry, activation energy and positional embeddings.

Central Tension & Control ManifoldActivation: 88.4% (Dim 142/512)

Encodes control of d4/e4/d5/e5 squares. Activates strongly during early central tension structures.

Research Lineage

Praxis is situated within a lineage of systems that progressively moved away from handcrafted game knowledge:

AlphaGo2016

Deep neural networks combined with Monte Carlo Tree Search, using policy and value networks to evaluate positions and guide search (Nature).

AlphaGo Zero2017

Removed human gameplay data entirely, learning from scratch through pure self-play reinforcement learning.

AlphaZero2017

Generalized the architecture to chess, shogi and Go with a single shared algorithm and zero game-specific heuristics.

Praxis StudioPresent

An experimental implementation and visualization laboratory making the internal dynamics of search, representation, and self-play telemetry observable.

The Research Question

“If we can watch an AI search through possible futures, can we better understand how learning changes the way it searches?”

Chess is the environment. Self-play is the data generator. The neural network is the evaluator. MCTS is the search mechanism. Telemetry is the microscope.

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