I think it's fairly easy to see why RDF has such a centralizing and stifling effect on metagames it's introduced to by looking at what it is and, as a result, what it allows you to do with combos.
RDF is the fusion of a small rubber flat tip, similar to a relatively fresh RSF or a heavily worn RS, and a wide outer plastic ring for LAD, like WD and its many relatives.
RDF carries over:
+ Top tier grip from RSF and other rubber Tips for top tier Defense
+ Mild aggressive movement like RSF / worn RS to enable light Attack use and interrupt stalling opponents
+ Top tier LAD from WD and company to dominate most opposite-spin matchups
- Poor same-spin Stamina due to high grip, though still significantly better than the typical Attack options of RF, R²F, or LRF
RDF giving you the desirable defensive/Anti-Attack properties of already top-tier parts like RSF and RS with the added cherry on top of massively improved LAD makes it a no-brainer pick for any role that those Tips previously would have filled. You still will lose to the same threats in same-spin as before, but your Defense combo will outspin any opposite-spin opponent with less LAD - which now means almost everything, as only EWD, W²D, and B
have greater LAD, and even then by a narrow margin.
This is a major problem with RDF. Its LAD, while not the best, is high enough that only a handful of parts are better, and those only by a narrow margin. CF, GCF, and GF can also potentially out-LAD RDF, but they generally need some other form of LAD advantage over the RDF combo to pull it off. RDF's LAD is close enough to the maximum possible in MFB that, by the very nature of opposite spin matches, it will force many battles where it technically is at a disadvantage to still end in a very, very close way, resulting in ties and/or the need for tedious match footage review. This compounds with another feature of RDF in these matchups - its Attack potential. All of the Tips that can OS RDF in opposite spin are vulnerable to Attack, and many combos that use RDF will have enough Attack power to potentially KO their would-be counters this way - and even if they fail, the high probability of the battle ending in an indecisive tie (or even a lucky OS for RDF) means that the RDF combo has extra chances to find that KO.
Fortunately, this all applies only in opposite-spin battles. In same spin, RDF is "only" comparable in performance to the most popular Defense (and off-meta Attack / Anti-Attack) tips...
But what if most of your opponents were opposite spin?
Limited's left-spin (and dual-spin) wheels LOVE RDF. Gravity and to a lesser extent Lightning are already controversial on low height RF as Attackers with extremely good Attack v Attack performance and enough LAD to win matchups vs Defense types. Switching to RDF costs them a significant amount of Attack power, but in exchange it gives higher same-spin Stamina (so they outspin other left-spin Attackers) and far greater LAD, so they maintain a clear edge vs the vast majority of the right-spin field, except for easily KOed Stamina tips like EWD etc and the much less easily KOed fellow RDF combos.
RDF is also the part L-Drago Guardian would *love* to have, as it synergizes well with its Anti-Attack playstyle while safely protecting it from its own rubber. Meteo, too, would enjoy having RDF as a more aggressive/defensive alternative to the typical EWD or CF combos.
In the end, what RDF does is enable players to create combos that are only really weak to same-spin opponents with at least moderate Defense and Stamina. They are great at covering a wide variety of matchups, soundly defeating Attack types in both directions, opposite spin Defense, and threatening Stamina types in both directions. As a powerful derivative of already top tier parts, RDF is very low-risk to use and offers potentially very high rewards. The avenues for reliable, safe counterplay are limited (and usually spin direction sensitive), so the metagame tends to be rather reactive to RDF specifically and can devolve deck-building into a guessing game as to which spin direction RDF will appear in (and so which way you need to prepare to counter). It also hurts the depth of the LAD metagame by being a strong Tip in many competitively relevant matchups in both spin directions with high enough LAD to outclass the vast majority of possible Tips and Track choices.
RDF doesn't make Defense any better at Defense, and it doesn't make opposite spin any better at LAD. What it does is centralize both of those parts of the metagame around a single part and force an increased number of battles to end in slow and ambiguous LAD contests. The combos that benefit from its introduction suddenly threaten much larger sections of the metagame than they did before, which dramatically reduces the variety of ways that you can respond. Different RDF combos also have significantly different matchup charts where one combo's strength could be another's weakness, so preparing for RDF is made even more difficult.
Don't let any of this discourage anyone from experimenting, and games with dubious or outright broken balance can still potentially be fun, but in my experience and testing, RDF's unique properties give it ultimately unpleasant effects on any metagame it can make use of them in.
Zero-G is safe from its dark influence, haha.
![[Image: Two-Spiderman-Meme-Template-on-Pointing-...ther-1.jpg]](https://i.postimg.cc/QXHp9CrS/Two-Spiderman-Meme-Template-on-Pointing-at-Each-Other-1.jpg)
![[Image: this-is-our-mfl.jpg]](https://i.postimg.cc/SsJGQvXT/this-is-our-mfl.jpg)