Bowling an entire block without an open obviously is not a common thing on the PBA Tour or PBA50 Tour: even when the scores are high, it’s rare to avoid leaving a pocket split, making an errant shot for a split or washout, or missing a spare in an entire block.
I remember it was a big deal to me when I did it for the first time in a PBA Regional in Moline, Illinois, in 1987, using a Brunswick GRAY RHINO! Perhaps my memory is strong because I won my first PBA Regional title that weekend....