Great reply Jay!
I got to know Mike in the 80s. I was introduced to the White Spot, in Fife WA, Wed nite tournament. In 1982. Not sure when Mike started coming to them. The White Spot had a weekly $5 tournament that was known. A bi-yearly $35 race to 7 bar box 9 ball tourney that fielded close to 64. It was the Big show for bar box. Even saw Swanee there once. I watched Dan Louie come back from 0-6 in a race to 7 in the finals. Not once but twice.
In the course of all those tournaments and encounters sweating action matches at Harry's in Lynnwood, Mike filled my head with knowledge, guess that is why we call him Gabby.