velocity

.java

@EventHandler
private void onVelocity(PlayerVelocityEvent event) {
    if (event.getPlayer().getLastDamageCause().getCause() != EntityDamageEvent.DamageCause.ENTITY_ATTACK) return;
    Player damaged = event.getPlayer();
    Vector vector = damaged.getVelocity();

    vector.normalize();
    if (!damaged.isSprinting()) {
        vector = new Vector(vector.getX() * this.horizontal, 1.0D * this.vertical, vector.getZ() * this.horizontal);
    } else {
        vector = new Vector(vector.getX() * this.sprintHorizontal, vector.getY() * this.sprintVertical, vector.getZ() * this.sprintHorizontal);
    }
    event.setVelocity(vector);
}

private double vertical = 0.35D, horizontal = 0.35D, sprintVertical = 0.55D, sprintHorizontal = 0.45D;