He missed a single-pin during his match with Chris Warren on Friday. It wasn't on the show. I think it was more than 475 in a row, though. He had all 475 last year (in match play; they don't mention qualifying), plus 47 this year, and they didn't comment on the previous year. And they no longer have the stats up, but over the past four or five years, there are maybe a half-dozen misses.
SH