IPSC Classification Explained in 60 Seconds (BLUF)

Short answer: IPSC ranks shooters into six classes — Grand Master (95%+), Master (85–94.9%), A (75–84.9%), B (60–74.9%), C (40–59.9%), and D (under 40%). The percentage is calculated against the highest hit factor ever recorded on a standardized Classifier Stage (CLS). You need a minimum of four CLS scores to get an initial class, and after that your classification is recalculated from the best 4 of your most recent 8 results. To keep your class active, you must shoot at least one classifier match or two CLS stages each calendar year, and your class is division-specific — being an A-class in Production doesn’t make you A-class in Open.