BM25 Ranking 2D: Search Score Bar Chart

Every keyword search engine has to answer the same question millions of times a second: given a query, which of billions of documents deserve to be shown first? BM25 is the classical answer — a probabilistic ranking function that balances how often a query term appears in a document against how rare that term is across the whole corpus, while penalizing documents that only look relevant because they are unusually long. This 2D companion draws a synthetic 18-document corpus as a live bar chart and recomputes every document's BM25 score as you pick query terms and drag the k1 (term-frequency saturation) and b (length-normalization) constants — the same two knobs that Elasticsearch, Lucene and Solr expose to real search engineers.