Someone asked me to add TSR to the website a while back and it appears on the Teamstats page. I was going to blog about TSR but then I found another page which actually does it very well. I’d end up copying stuff from there so it makes more sense if I just point you in that direction if you want to know about it.
http://pena.lt/y/2013/04/02/understanding-total-shot-ratio-in-football/