I haven't read beyond BSims' original post. Some basic thoughts on the topic:
* Kelly is a sound betting practice.
* Most experienced players will opt for a reduced Kelly bet-size, like 1/2-Kelly, to not be overly aggressive.
* The real catch-22 is that the HARDEST calculation for the sports-bettor is PROSPECTIVE win-rate. This isn't like dice or cards, which have fixed odds. The NEXT bet you make is speculative, and therefore it's extremely hard to pin-point your expected future win-rate.
BSims, per usual, your content provides good food-for-thought. Have a nice wkend, and Good Luck.