This sounds like barn door statistics!
How to understand this phrase?
The answer from above wiki link is so much fun it must be worth entering here on the ELU site;
The name is from a joke about a shifty Texan who shoots at a barn, then paints a target centered on the tightest cluster of hits, then claims to be a sharpshooter!
It refers the tendency of some , to infer trends in statistics where none exist.