Sometimes it's worthwhile to just look at all the places the pari-mutuel dollar goes in racing. With that in mind, I've returned to the well-done California Horse Racing Board annual report for fiscal year 2015-16, which breaks down where every pari-mutuel wagering dollar goes in the state.
Of the $2.9 billion wagered on California racing in the fiscal year, $2.3 billion, or 79%, was returned to winning ticket holders. The graphic on this page examines where the 21% retained as the takeout from those $2.9 billion in wagers--some $600 million for all breeds--is distributed. The numbers listed in the boxes are the percentages of that total takeout.
Wagering generated $131,788,209 in purse money and $112 million for track commissions. It also generated $151 million for tracks and purses in other states through wagers made at out-ofstate tracks on California races (in the chart this is listed as "other states takeout").
Those three sources account for 71% of the money generated. The "expense fund" (6.41%) benefits off-track betting outlets and is designed to offset costs of in-state simulcast broadcasting.
The graphic below is from the CHRB annual report.