May 2008
Volume 8, Issue 6
Vision Sciences Society Annual Meeting Abstract  |   May 2008
Baseball's paradoxical pop up: Physics and fielder control strategy can lead to lurching
Author Affiliations
  • Michael K. McBeath
    Department of Psychology, Arizona State University
  • A. Terry Bahill
    Department of Systems and Industrial Engineering, University of Arizona
  • Alan M. Nathan
    Department of Physics, University of Illinois
Journal of Vision May 2008, Vol.8, 623. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Michael K. McBeath, A. Terry Bahill, Alan M. Nathan, David G. Baldwin; Baseball's paradoxical pop up: Physics and fielder control strategy can lead to lurching. Journal of Vision 2008;8(6):623.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

We describe how current baseball physics models predict a class of towering pop ups in which the ball trajectory is steep enough to exceed the angle of repose, resulting in upward curvature. When optical interceptive control strategies like Optical Acceleration Cancellation (OAC) and Linear Optical Trajectory (LOT) are applied to such trajectories they produce systematic vacillations in running paths. We refer to these fly balls as Paradoxical Pop Ups because they behave fundamentally differently than typical near-parabolic fly balls. Paradoxical Pop Ups comprise a unique set of trajectories that can exhibit discrete cusps and loops near the apex, and tend to be more symmetric than typical. These trajectory abnormalities appear to misinform the typically robust optical control strategies used by fielders, which can lead to systematic lurching, especially when the pop up is headed to land near the fielder. It is useful for perception-action modelers to be aware of these deviant cases given that a number of research laboratories that study interception currently use near-parabolic models of ball trajectories in lieu of direct location measurements. In short, current perception-action research may benefit from more accurate physical modeling. In the case of fielders pursuing paradoxical pop ups, some of their dancing around can be well explained as a combination of bizarre trajectories and misguidance by the normally reliable optical control strategy, and is likely not due odd wind conditions, too much chew tobacco, or apparent fielder error. Behaviorally, even professional baseball players occasionally find it difficult to gracefully approach these seemingly routine pop-ups, and former Major League infielders confirm that their experiences agree with our predictions.

McBeath, M. K. Bahill, A. T. Nathan, A. M. Baldwin, D. G. (2008). Baseball's paradoxical pop up: Physics and fielder control strategy can lead to lurching [Abstract]. Journal of Vision, 8(6):623, 623a,, doi:10.1167/8.6.623. [CrossRef]

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.