The story, when it comes to the concept, sounds very been there done that initially, or at least that is the case with the first quarter. There are a good deal of 'Law and Order: Special Victims Unit' episodes, and episodes even in the 'Law and Order' franchise, that have stories and themes done before, but they do something a lot less simple and more complex than it seems with them. They are though themes that are worth addressing and need to be.
My review is most likely not going to be well received, but "Sport of Kings" is really not one of my favourite episodes. As far as Season 15 goes, it's towards the bottom. Not in any way a terrible episode, don't think any 'Law and Order' episode fits that distinction (despite overtime having some terrible elements, such as the ending of "Ain't Gov Love". It is also not too great and what should have been potentially twisty and taut turned out to be rather mundane, this is being said with regret.
"Sport of Kings" has good things. The production values are solid and the intimacy of the photography doesn't get static or too filmed play-like. The music when used is not too over-emphatic and has a melancholic edge that is quite haunting. Things do pick up a little later on, where there is some more tension.
Also think that most of the performances were fine, Sam Waterston taking top honours in his usual authoritative and ruthless way.
Michael Imperioli for my tastes was still bland, as was his chemistry with the better faring Dennis Farina. Fred Dalton Thompson looks and sounds particularly bored. The dialogue could have been tauter, especially early on.
On the whole, the story didn't grab me. It feels rather over-stretched and draggy to begin with and then rushes too much towards the too hastily wrapped ending. Adding to the dullness was the predictability, no real surprises here.
In conclusion, watchable but far from great. 5/10.