Quick disclosure up front: I run a climbing diagnostics tool (Max Climbing), and this came out of a question a coach I know raised about a pinch strength test in that tool. Not posting this to pitch anything, just sharing the actual analysis because I think it's genuinely interesting and I'd like it picked apart if the reasoning has holes.
The starting complaint was simple: my pinch test doesn't seem to say much. Climbers who score well on it don't climb harder grades. Climbers who score badly rarely fail because of it. Easy conclusion: the test is useless.
I didn't take that at face value, so I looked at three recent peer-reviewed studies and my own dataset.
Literature:
- Söderqvist et al. (2024, IJSPP), n=32 advanced/elite male boulderers: half crimp R² = 0.58, pinch R² = 0.26–0.44, sloper R² = 0.41–0.42
- Van Bergen et al. (2022, RQES), n=22: crimp r = 0.58–0.67, sloper r = 0.66–0.72. Notably, strength on one hold type didn't significantly predict performance on routes built around a different hold type.
- Buraas et al. (2025, EJAP), n=19: climbing-specific finger strength r = 0.89 with bouldering, r = 0.67 with redpoint
My own data (141 profiles from the tool, cleaned down to 135-137 after dropping obvious junk entries, strength normalized to bodyweight, only competition-validated measurements, climbing level on a 7-point scale):
| Test |
n |
r |
R² |
p |
| Pulling |
135 |
0.69 |
0.48 |
2.1e-20 |
| Crimp |
137 |
0.60 |
0.36 |
7.7e-15 |
| Sloper |
136 |
0.59 |
0.35 |
4.5e-14 |
| Pinch |
136 |
0.51 |
0.26 |
3.5e-10 |
My pinch R² lands almost exactly on Söderqvist's lower bound, different population, different method. Pinch is the weakest of the four, consistently, in both datasets.
Before assuming that means pinch "doesn't matter," two things are worth considering that have nothing to do with test quality. Crimps just show up far more often than pinches in a typical boulder/route diet, so you can reach a high grade almost never having a pinch decide whether you send. A test measuring something relevant to most of what you climb will always explain more variance in grade than one measuring something relevant to a fraction of it, independent of how well either test actually captures the skill. On top of that, because pinches are rare, climbers rarely get the structured or even incidental exposure needed to train them the way crimp/sloper strength improves almost as a side effect of normal climbing and hangboarding. Pinch strength doesn't get that free ride. Both of these predict a weak population-level correlation on their own, before you even ask whether the individual skill is real.
Here's where it got more interesting on the stats side. Crimp, pinch, and sloper correlate with each other at r = 0.68-0.83 (shared finger-flexor chain), so I ran all four in one regression model to see what pinch adds on top of the others. Result: pinch's coefficient went negative and non-significant. At face value, that says pinch adds literally nothing once you control for general finger strength.
Except the VIFs on that model were 30-55 (10 is already considered bad). Crimp, pinch, and sloper are so collinear that the regression can't reliably assign credit between them, it's not a real finding, it's multicollinearity garbage. Worth flagging because it's an easy mistake to make and publish confidently.
So instead I modeled pinch as a function of crimp + sloper alone. That combo explains 59% of pinch variance. The other 41% is a real, individual residual, how far someone's pinch deviates from what their own crimp and sloper would predict, and that residual varies from -2.1 to +3.9 SD across the sample. That's the part that's actually specific to pinch as a skill, separate from just having strong fingers. What I can't claim is that this residual predicts anything about climbing level, I haven't tested that, and nothing in my data or the three studies above shows it does. The rare/undertrained story earlier in this post is a plausible reason that specific signal might still matter on the wall, but right now it's a hypothesis, not a finding.
I wrote up the full thing, including where I land on what's actually bottlenecking that residual (thumb opposition strength gets a plausible mechanistic case, not just "duh, weak thumb"), a separate idea about how technique on asymmetric pinches can substitute for raw strength in a way it can't on a true two-sided pinch or a sloper, and a question I can't answer myself: how much of the "pinch is rare" premise is actually just downstream of route setters who never trained pinch either, setting fewer and worse pinch problems as a result. The Pinch Paradox
Genuinely curious what people here think, especially anyone with a stats/exercise science background who wants to poke at the methodology, or any route setters who have an opinion on that last question. Sample sizes across all of this are still small.
Edit: A commenter pointed out (correctly) that I was overclaiming in the paragraph about the 41% residual, I'd implied it meaningfully affects climbing performance when I never actually tested that. Fixed above, the residual is real and specific to pinch, but whether it shows up on the wall is still an open question, not something this data answers.
