In baseball, a no-hitter is a game where no batter on a given team makes it to first base after hitting a fair ball. They can still however make it to base via other rules. So in theory, runs (points) could still be scored even if nobody scored a hit.
A game in which there are no-hits and no-runs is called a 'perfect game'.
So, pitching a no-hit no-run ball game means pitching a perfect game.
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