How to read the grid
Pio V4 (new) faster
Pio CFR (old) faster
4 bars = the accuracy targets 0.5 → 0.05% pot (left→right); colour = faster algo,
height = how much faster (linear 1× … ≥2.5× = full; empty = neither reached)
number = overall speed-up (geo-mean over targets both reached, 0.05% excluded)
≥ N× — faster algo also reached targets the other never did, so the real gap is even bigger
≫ — the other algo reached no target within the time budget (no finite ratio)