Post
The consistency of time between frames, often more important to perceived smoothness than raw framerate.
A game running at 60fps with perfectly even 16.6ms frame times feels silky. A game averaging 60fps but oscillating between 10ms and 25ms feels chunky even though the number is the same. Frame pacing focuses on variance, not mean. It is why V-Sync, VRR displays, and frame-time graphs exist, and why benchmarkers increasingly publish 1% low and 0.1% low framerates instead of just averages.
Example
Digital Foundry's analyses made frame-pacing mainstream discourse around 2015. The PS4 version of Bloodborne had notorious frame-pacing issues despite hitting 30fps nominally. Nvidia's G-Sync and AMD's FreeSync exist specifically to solve frame-pacing mismatches.
Why it matters
Frame pacing is why two games with identical framerates can feel entirely different. Understanding it is essential for evaluating optimization work, comparing platforms, and diagnosing why a game 'feels bad' even though the FPS counter looks fine.
Related concepts