This would be more interesting if, instead of throwing the ball while standing at the water's edge, the human stood further back up the beach as in the lifeguar

This would be more interesting if, instead of throwing the ball while standing at the water's edge, the human stood further back up the beach as in the lifeguard illustration. [1] This would require the dog to decide on the path to take at the start, or run in a path that wasn't a straight line. Anecdotally, when performing this experiment in the past, my dog typically runs directly towards the ball along the straight-line path Lifeguard->A, then turns somewhat along the edge of the beach to plunge in somewhere between A and C. I'm also curious if there is a confounding factor in the dog's motivation. Pennings states [2] that: > By the look in Elvis’seyes and his elevated excitement level, it seems clear that his objective is to retrieve itas quickly as possible rather than, say, to minimize his expenditure of energy. There is obviously a value that the dog ascribes to the expeditious retrieval of the ball, but when the ball is not present there's also a value to be had in simply running joyously on the sand, and, of course, there's little better than being in the water. We may therefore need to calculate the ideal path based on a static value (perhaps 100 dog-utilitons) for retrieving the ball, plus 2 du/m running in the sand, and 12 du/m when swimming in the water. This complicates the mathematics somewhat. Finally, the author's method of running ahead with a tape measure may work when measuring the performance of a short-legged subject, but I would be unable to use these methods to measure the performance of my larger and faster (Newfoundland) dog. Aerial drone videography may be more suitable instead. [1]: https://d3chnh8fr629l6.cloudfront.net/2904_b8b9c74ac526fffbeb2d39ab038d1cd7.png https://d3chnh8fr629l6.cloudfront.net/2904_b8b9c74ac526fffbe... [2]: https://webcache.googleusercontent.com/search?q=cache:l0DmOIr4uhsJ:www.indiana.edu/~jkkteach/Q550/Pennings2003.pdf+&cd=1&hl=en&ct=clnk&gl=us https://webcache.googleusercontent.com/search?q=cache:l0DmOI...