I really enjoyed running #4.  I tried running Libby with the same kind of lead out as Dusty, i.e., between 3 and 4, and also just leading out between 1 and 2 and running with her.  When I looked at the counter on the tape, I found that the shorter lead out produced the faster run by approximately .8 of a second.

Exercise #4 went really well for both dogs, although Dusty brought down the bar before the WP as he caught up to me and leaped into the air.