There really isn't much math to it at all.
If a team intentionally fouled Rondo on 10 consecutive possession and he converted 10 of the 20 free throw attempts, it'd be the same as if the Kings shot 5 for 10 (50%) from the field under normal circumstances. Any team not named the Warriors would take that.
To me, the tactic is really only useful at the end of games. Obviously, you can't foul away from the ball the last 2 minutes -- but I'm referring to fouling Rondo each time he touches the ball.
The manner in which Carlisle used it last night is quite dumb, IMO. Too much time left in the game and it takes you out of your own offense due to all the stoppage in play. You can't get in a rhythm.
However, in the last 90 seconds of a game when all the pressure is on -- it's a great tactic. And Coach Karl may need to get the ball in the hands of Collison and Curry more often in those situations.