I could wax a bit more eloquent when it comes to introducing subject, but Virtua Fighter has never spent much time with frills and ceremony, so why should I? If grand pronouncements must be made, I can at least say that this is the best of the four Virtua Fighters in almost all aspects, a compilation and distillation of what worked over three complete games and ten years of intense 3D fighting competition. Enough games of VF have been played worldwide to plumb every tiny depth of every one of these games, down to each frame of animation, and the feedback from all that fighting is what made this game. Made it very, very good.
It's still Virtua Fighter, certainly, but with its good points magnified and flaws diminished. VF2's straightforward ground-based game is maintained, but the force of gravity is implemented to make aerial attacks more realistic. VF3's experiment with 3D movement yielded mixed results, but its advancements aren't entirely discarded in VF4 -- it's possible to explore the arenas more freely than VF2 allowed, there's just a little more method to 3D movement, and none of the chaotic evasion found in VF3. In both of those games, grappling and reversal schemes proved a worthwhile component of advanced strategy, so now there are even more different types of countermoves, although they're still difficult enough to remain the tools of experts.
While the excruciatingly detailed timing and positioning strategies should be familiar to fans of the series, there are still kinks to deal with here and there. VF is still a heavy pressure game (nothing will ever change the huge okizeme component to advanced strategy), but it's coming from somewhat different quarters nowadays. The edges of the ring, for example, work much differently from earlier games. VF3 introduced the new dimension of wall pressure and reduced the significance of ring-outs -- VF4 goes even farther in both of those areas, adding more walls and less edges, but it also introduces much larger arenas all round, meaning less dithering about ring-outs and more toe-to-toe fighting.