I love Battle 3, I really do, and I won't be going back to B2P anytime soon (and I really liked B2P BS 39).
I believe there is strong correlation between observation, and the claims made by 729 about the R&D invested into this rubber. Furthermore, now that I know the full story (several years delay to its release due to the pandemic, which also meant less funding to advertise), it's understandable why its performance isn't matched by its popularity.
Specifically, once broken in, the B3 40 (despite the +1 hardness) has better mid-range than the B2P blue sponge 39, while being slower (more controlled) for service and pushes (that's a good thing). However, like I mentioned in my previous post, the top-end extension feels beyond my ability, without resorting to a flat smash. Even then, I've not noticed any misbehaviour so I'm not actually sure if I'm bottoming out the sponge or not.
But it takes time to get the most out of Battle 3.
Don't get me wrong, I personally liked how it played brand new. New rubbers always have that nice, unique feeling for the first half hour of play. It's just that it gets significantly better once broken in.
On that note, I'm going to hypothesise and labour the breaking in aspect of Battle 3 for a minute.
My excuse... sorry, I meant, the reason for doing so is that I think it's an important data point for anyone thinking about buying it, including why I think the price is justified, and worth the effort/time
(the reality is that I just wanted to type out my thoughts on the matter. So I did).
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The below is a technical tangent based on experience, not specific research.
Stop reading if you don't like such tangents.
TL;DR
In my opinion, there are (potentially) sound mechanical reasons behind why B3 takes longer to break in, which could also significantly improve its durability vs. a typical sponge structure (all else being equal).
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Objectively, B3 takes longer to break in than B2P or B2P BS (and Gold Arc 8 50, for that matter). As such, I sincerely believe that you cannot honestly judge B3 within the first few hours of
hard play. Anyone providing a review of Battle 3 after one session is misleading you (it may not be intentional, but its misleading nonetheless).
But why?
My guess: 729's new sponge-forming technology.
Apparently, this method results in an even distribution of two distinct groups of pore sizes (bubbles, essentially) throughout the sponge, such that larger pores are surrounded by a regular number of smaller ones. It's not exactly analogous, but it seems quite similar to the way smaller atoms fill the interstitial voids of an alloy. The benefits of this are numerous, and also apply at multiple levels (from atomic to macroscopic), such that the same general principles/benefits pop up in many areas of engineering that involve the mechanics of solids and/or structures.
This structure should distribute point loads more effectively, such that peak internal stresses within the material itself are significantly lowered. If true, this would necessarily require more load cycling (and higher peak loads) to "break in" the sponge.
Therefore, taking longer to break-in—though it might be an unintentional, but happy by-product—is an inherent property of this sponges mechanical structure compared with random porosity or fixed size porosity, all else being equal.
What is break in, exactly?
Well, I don't know, exactly, as I've never looked into it, but my gut feeling is that it's not the same as the fatigue-related failure mode, which all rubbers undergo, as they wear out from intentional use. It probably has more to do with the release of uneven internal stresses, or other anomalies, within the structure (via plastic deformation or fracture). Ideally, the sponge should have homogenous mechanical properties throughout, such that the relief of uneven/unintentional internal stress is not required (or possible), however, that is never the case, and so break in occurs.
But again, this is all from my own rationalisation based on experience with other materials, combined with a lot of observational evidence from the modern TT community. I've no actual evidence to support any of this.
So if you read this far and don't know why, don't say I didn't warn you.
