In efforts to learn more about the baseball stat “GmSc,” I did a Google search, which led me to the Grande Maumelle Sailing Club, which led my wandering mind to the yacht club in “Caddyshack,” which led me to YouTube “Caddyshack” scenes, which led me to nearly noon without finishing this paragraph.
“GmSc” stands for “game score,” a stat featured on baseball-reference.com. In short, it's a number that shows how good a pitcher's start was, while using a Bill James formula:
Start with 50 points. Add 1 point for each out recorded, (or 3 points per inning).