Been revisiting Modern Army Combatives, by Matt Larsen, This is a good book. It does some of the others on the subject out there one better, and gets beyond “BJJ in BDUs” and while answering many of the “yeah but..” questions that arise when considering combat sport as combatives preparation. Modern Army Combatives anticipates and answers the problems and pitfalls that arise with competition oriented fighting, addressing firearms and contact weapons issues as well. Though specifically directed at military situations, there is direct relevance to law enforcement concerns, and the material is readily adjusted for civilian defensive situations.
Larsen offers a number of ideas for sparring, drills, and other training that can help any instructor, academy, or gym translate their combat sport training into real combative utility. Whether as confirmation of what you already know, or looking for ideas on how to do more with training than a standard grappling class, this book has it.