Krapivin-Block-Tracker

We present the Krapivin-Block-Tracker (KBT), a hybrid data structure combining Elastic Hashing / Funnel Hashing (Farach-Colton, Krapivin, Kuszmaul 2025,arXiv:2501.02305) with a compact hysteresis tracker in L1-cache. The tracker eliminates unnecessary probes into overfull blocks and reduces tracker update frequency by up to 307,838× compared to a single-bit marker. Probe cost with the tracker is exactly 1.00 per insertion across all tested regimes. The analytically derived critical point δ* = 0.20, at which the hysteresis gain collapses, is confirmed by simulation. Includes Python simulation scripts and chart generation code.