I remember Vin Scully's call of the ninth inning of Sandy Koufax's perfect game on September 9, 1965. You can listen to it here. Remember, this was a live unscripted description of an on-going event.
I listened to that game live as well. It’s only after hearing it again, after all these years that I appreciate how good Vin is—as you say, an unscripted description of what was happening as it happened. That is how he has spoiled those of us lucky enough to have grown up listening to him.
I don’t know if you grew up in the L.A. area, but in the early days at the Colosseum people would bring transistor radios to the game so they could hear Vin’s broadcast. Easterners thought it was because West Coast Dodger fans were just unsophisticated as far as major league baseball was concerned and needed help following the game. The fact is, the game is better when you hear Vin.