[HN Gopher] Open-source motion capture data of elite-level baseb...
___________________________________________________________________
Open-source motion capture data of elite-level baseball pitchers on
GitHub
Author : icelancer
Score : 56 points
Date : 2022-12-14 10:45 UTC (1 days ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| rcarr wrote:
| Only tangentially relevant but there is a great comedy drama show
| on Amazon Prime at the minute about the forming of a professional
| women's baseball team during WW2 called A League Of Their Own.
| arrosenberg wrote:
| Everything gets a remake I guess...
|
| https://m.imdb.com/title/tt0104694/
| williamscales wrote:
| This is from Driveline Baseball. My understanding is that they've
| really revolutionized the ability of pitchers to put spin on the
| ball. (Sticky stuff aside)
| Kon-Peki wrote:
| The MVP Machine [0] has a lot of interviews and background with
| Driveline folks, including their now-disgraced-turns-out-hes-a-
| terrible-person headline player (Trevor Bauer).
|
| What's unclear is how long-lasting the performance improvements
| are (can the pitcher maintain spin rates without constantly
| going back to the data and coaching staff?).
|
| One very positive thing I've seen is applying the analytics to
| young athletes as a future injury prevention tool. We now can,
| with high probability, identify kids who are on the path to
| permanently ruining their arm long before they cause lasting
| damage and give them an intervention - "You can dominate in
| Little League, but you'll never be a pro if you keep doing it
| this way. You must either change the way you throw or stop
| trying to be a baseball pitcher"
|
| [0] https://www.basicbooks.com/titles/ben-lindbergh/the-mvp-
| mach...
| clusterhacks wrote:
| Good book! I think the Driveline blog is a better source for
| folks working with youth athletes. The MVP Machine was a
| little bit more Moneyball than player development oriented .
| . .
|
| Bauer. I had a bit of a meltdown about him - I was
| momentarily worried that his name alone would bring a huge
| negative reaction to people associated with Driveline
| training methods. That seems to have not come to pass.
|
| I very much like the Driveline "Skills that Scale" training
| approach. I took several brand-new-to-softball middle
| schoolers into 50+ MPH bat speeds with overload/underload
| training and bat sensors. One great athlete hit 60+ in
| training in her very first year of playing the game. Course,
| she looks like a D1 athlete as well, so she may have gotten
| there just by putting a bat in her hand . . .
| noja wrote:
| RTIB/LTIB and RTHI/LTHI are not symmetrical - any idea why?
| bena wrote:
| Just spitballing and guessing here: easier math.
|
| Look lower down at the pictures or pitchers (heh). The legs
| themselves aren't symmetrical.
|
| So they probably tweaked the points so that the most common
| range of angles to make the math easier to do.
|
| Like I said, just a guess. But with one leg bent and the other
| stretched out, they probably form a line close to parallel with
| the ground for right-handed pitchers at the point in time when
| the pitcher is transitioning from wind up to release.
| allenofthehills wrote:
| Marker placement in motion capture is often intentionally
| bilaterally asymmetric because it makes automatic labeling of
| markers easier (with respect to side/orientation of the
| subject).
|
| Source: Am a biomechanist with several years of mocap
| experience.
| Cyberdogs7 wrote:
| I can answer this. Each of these markers comes into the
| software as part of an unconnected point cloud, which then
| needs to be identified and 'solved' to a constraint skeleton to
| get the true angles of rotation and the 'stick person'
| representation that you typically see.
|
| Because of this, if you placed markers with bi-lateral
| symmetry, it would be much more difficult to solve joint
| rotation angles, as the overall facing of the point cloud would
| be undetermined. So, you have additional markers placed on none
| moving (not a joint) locations that ruin symmetry and allow
| facing to be easily solved. Typical locations are outside of
| the thighs, upper arms, and occasionally the back.
|
| I built mocap studios for games companies.
| manglav wrote:
| that's amazing! Do you have an email address where I can
| shoot you a message? I'd love to pick your brain on this tech
| (paid of course).
| bena wrote:
| I was mostly wrong.
|
| But I like this answer better. It's a simple and clever
| solution to a real problem that you might not readily see as
| you're developing the solution.
| keepquestioning wrote:
| All this effort going into the most boring sport imaginable.
| voidfunc wrote:
| I thought we were talking about baseball not soccer.
| clusterhacks wrote:
| Driveline is the cutting edge of baseball/softball hitting and
| baseball pitching. As a tech person involved in coaching youth
| through middle school athletes, their blog (and youth coaching
| certification, which I completed) really gives a solid foundation
| in how to use bat speed sensors, radar guns, and more advanced
| tech in training. It's fun stuff for a data geek.
|
| Mocap is a step beyond what I want to do with young athletes but
| having a data-driven approach is a coaches dream. Measure things
| that matter, build a constraint-based training environment, and
| let exterior outcomes shape players.
___________________________________________________________________
(page generated 2022-12-15 23:02 UTC)