So after my expert 3bv run, I decided to run the corresponding int batch.
This time I also kept track of openings, so I have a 2-dimensional table of data here: http://pastebin.com/raw/fXtWPRRR
The highest and lowest 3bv's I found were 7 and 172. I saved all sub 12's and sup 160's. The fewest openings as expected was 1, occurring at a rate of about 1 in 6500.
The most openings I found was 22, which occurred 3 times.
The most common combination of opening and 3bv is 7 openings with a 3bv of 63 occurring 0.735% of the time.
Average 3bv: 64.9217
Standard deviation: 11.6961
Most common 3bv: 63 (3.429% of boards) but only just barely after the
Second most common 3bv: 64 (3.424% of boards)
Most common openings: 7
log 3bv plot: