I think he was something like -3 wins, but early stats weren't very comprehensive so that's mainly hand waving. Keep in mind that up until now, we haven't had enough data to really determine individual defense fairly (granted Jeter has a large enough body of work that it is probably pretty accurate for his career). With the new data systems now in place, we have defender's position, ball trajectory and velocity, speed, defender reaction times, etc (well we may not, but teams do). It should be possible to determine exact defensive ability to very good accuracy going forward.