I think that climbing won’t be distilled into numbers being a movement sport.
I’ll preface the rest of my post by acknowledging that I have not spent any time measuring climbers nor have I tried to correlate any data gathered by others on climbers to make statements around their performance.
Certainly, there are numbers that correlate. PCC has proven that. But, that word “correlate” is key, and it is worth emphasising just as @Kris did.
There are other sports where it is arguably easier to identify a deficit.
I would be willing to argue that the easiest sport to analyse numerically is strength. Charles Poliquin was a big believer in comparing ideal strength levels between lifts. I believe that Poliquin’s Structural Balance material presents some ratios between various strength movements.
Even then, those ratios aren’t perfect as different body types might have leverages that are advantageous for some lifts and disadvantageous to other lifts. Similarly, having more experience with one movement might make it artificially elevated. Experience is something I believe can have an impact on the measurements gathered by PCC too.
Despite this drawback ratios can be a useful tool for identifying weaknesses and figuring out where best to invest training time.
Dan John talks about this with shot putters, so now we are a bit removed from exercising strength on a measurable barbell. When I’ve heard him mention this it is usually to tell a story of someone that is beyond adequately gym strong for the sport. If you are stronger at every meaningful lift for the sport of shot putting than the current record holder, you don’t need more time in the gym, you need to spend more time throwing.
That idea I see is shared by @Pisyphus ,
But for climbing, I’m not convinced it will prove as readily distilled into numbers. I believe the intricacies of the sport makes it too hard. As @Pisyphus highlights, flexibility and mobility is great but if you have those tools maybe you are drawn to climbs where you can leverage those tools.
Before I sent my first 7A I could deadlift 2x my bodyweight, and do chin-ups with ~55% BW attached but surely there are climbers climbing higher grades without those strength feats. And, maybe there are climbers that have the same capacity for strength as I did, but they don’t have to use as much of it on a hold as I do as they position themselves better in relation to that hold. And that causes an endogeneity problem, it’ll not be feasible to tease apart which variable is at play.
I’m confident there are meaningful screens for climbing athletes to do, but maybe they’ll translate more into having a robust enough body for the demands of the sport. I’ve been seeing this recently with the Kneesovertoesguy who was mentored by Poliquin has arrived at his own metrics for athletic potential. While his focus is more on the lower body he does have some upper body standards that if you meet them, then that’s not where your problem is, at least not for the sports that he focuses on.
Leaving finger strength and pull-up prowess aside I have a gut feeling that climbing will have similarities to gymnastics. For instance, if a climber can hold a bridge and they manage that movement by having adequate thoracic extension then I believe that to be a good thing in general for climbing performance but it probably won’t be a game changer. But it might mean less shoulder injuries after climbing for ten years. And the core strength to hold a front lever probably has utility on overhangs. Being able to do an explosive one-legged squat is probably more beneficial than doing a heavy back squat.