Real price drops, scored against each product's own history. No filler, no fake list prices.
Eight signals, weighted. How deep the drop is, how close to the lowest price ever seen, how rare a discount this size is for this exact product, how well it sells, and whether the price is fresh or fading.
A 15% drop on something ranked #50 beats 40% off something ranked #40,000. One is a purchase you were making anyway. The other is a gamble on a product nobody buys.
Above 80 is rare on purpose. If everything were green, green would mean nothing.