knockback / velocity issue in Minecraft Java Edition 1.21.4 that significantly affects PvP gameplay

Hello Mojang Studios Team,

I’m writing to report what appears to be a knockback / velocity issue in Minecraft Java Edition 1.21.4 that significantly affects PvP gameplay, especially in Sword FFA–style combat.

Since updating to 1.21.4, knockback behavior feels noticeably faster and more exaggerated than in previous versions. Players are frequently launched sideways or upward at unusually high speed, and velocity seems to stack when hits occur close together. This happens even without enchantments or external effects.

From player testing and observation, this does not appear to be a visual issue or placebo. The behavior is most noticeable when sprint resets, high CPS, or fast hit registration occur, suggesting that velocity packets or sprint knockback bonuses may be applying too frequently or without sufficient cooldown. Compared to earlier versions (such as 1.20.x), combos resolve much faster and are harder to control, making PvP feel inconsistent.

This issue is widely noticed across multiple servers, including vanilla-based PvP modes, which suggests it may be tied to core combat or movement mechanics rather than server-specific plugins.

If possible, I’d recommend reviewing:

Sprint knockback application timing

Velocity packet stacking in rapid hit scenarios

Differences in knockback calculation compared to 1.20.x

Thank you for your time and for continuing to support Minecraft. PvP players would really appreciate any investigation or clarification on whether this behavior is intended or a regression.

Kind regards,
A Minecraft Java Edition player