Update README.md

README.md

@@ -5,15 +5,6 @@ tags:
 - stockfish
 pretty_name: Lichess Games With Stockfish Analysis
 ---
-# Welcome
-Hello, everyone!
-<br>
-I will give you a quick overview of the data format and a guide on how to use the dataset.
-I always appreciate feedback and discussions. You can speak out [here](https://huggingface.co/datasets/mauricett/lichess_sf/discussions).
-And now, enjoy...
-<br>
-<br>
-
 # Condensed Lichess Database
 This dataset is a condensed version of the Lichess database.
 It only includes games for which Stockfish evaluations were available.
@@ -21,37 +12,55 @@ Currently, the dataset contains the entire year 2023, which consists of >100M ga
 Games are stored in a format that is much faster to process than the original PGN data.
 <br>
 <br>
-
-# Requirements
+Requirements:
 ```
     pip install zstandard python-chess
 ```
 
-
-
-
-# Quick Quide
-Using this dataset should be straightforward, but let me give you a quick tour. At the end, you find a complete example script.
+# Quick Guide
+In the following I help you understand the data format aswell as using the dataset. At the end, you find a complete example script.
 
 ### 1. Loading the dataset
-I recommend streaming the data, because the dataset is rather large (~100 GB) and I will expand it in the future.
+You can stream the data without storing it locally (~100 GB currently).
 Note, `trust_remote_code=True` is needed to execute my [custom data loading script](https://huggingface.co/datasets/mauricett/lichess_sf/blob/main/lichess_sf.py), which is necessary to decompress the files.
 See [HuggingFace's documentation](https://huggingface.co/docs/datasets/main/en/load_hub#remote-code) if you're unsure.
 ```py
-    # Load dataset.
-    dataset = load_dataset(path="../FishData/lichess_sf_test.py",
-                           split="train",
-                           streaming=True,
-                           trust_remote_code=True)
+# Load dataset.
+dataset = load_dataset(path="mauricett/lichess_sf",
+                       split="train",
+                       streaming=True,
+                       trust_remote_code=True)
 ```
 <br>
 
-# Data Format
-After loading the dataset, you can already check out how the samples look like:
+### 2. Data Format
+After loading the dataset, you can check how the samples look like:
 ```py
 example = next(iter(dataset))
+print(example)
+```
+
+A single sample from the dataset contains one complete chess game as a dictionary. The dictionary keys are as follows:
+
+1. `example['fens']` --- A list of FENs in a slightly stripped format, missing the half-move clock aswell as the fullmove clock (see [definitions on wiki](https://en.wikipedia.org/wiki/Forsyth%E2%80%93Edwards_Notation#Definition))
+2. `example['moves'] --- A list of moves in [UCI format](https://en.wikipedia.org/wiki/Universal_Chess_Interface). `example['moves'][42]` is the move that led to position `example['fens'][42]`, etc.
+3. `example['scores'] --- A list of Stockfish evaluations in units of centipawns, stored as strings. If the game ended in a checkmate, stalemate or draw by insufficient material, the last elements of the list is 'C' (checkmate), 'I' (insufficient material) or 'S' (stalemate).
+4. `example['WhiteElo'], example['BlackElo']` --- Player's Elos.
+<br>
+
+The dictionary contains 1) player's Elos, 2) all game positions as FENs, 3) all moves, 4) all Stockfish evaluations and/or the outcome condition.
+The FENs are slightly stripped. I removed the half-move clock aswell as the fullmove number. See the [definition of FEN](https://en.wikipedia.org/wiki/Forsyth%E2%80%93Edwards_Notation#Definition).
+```py
+fens = example['fens']
+moves = example['moves']
+scores = example['scores']
+white_elo = example['WhiteElo']
+black_elo = example['BlackElo']
+```
+Every sample drawn from the dataset will have a different number of FENs, moves and scores, but within a single sample we have
+```py
+len(fens) == len(moves) == len(scores) # True
 ```
-A single sample from the dataset contains an entire chess game as a dictionary. The dictionary has the k
 
 
 ### Usage