Basically yes, there are some issues with rounding, and I'll give you more exact numbers in another post (I've done some fine-tuning as I found some AM's based on incomplete matches). But yes your numbers and breakdown are basically correct. One thing I have to caution about, however, is that the 77%-70% is a truer comparison of the styles used in these matches, rather than the 57%-43%, because the latter only takes a snapshot of the "top" of the cone, so to speak, where the difference between the two styles looks more pronounced. Nevertheless it's interesting to break down everything the way you did and see just how many matches were won exclusively in one way (making fewer UE's) and how many were won exclusively the other way (making greater number of forcing plays). I've done some further sorting of the data and I think with relative ease I can get a list of the matches that were won ONLY with fewer UE's, and another list of the matches won ONLY with more forcing plays. Looking at my list chronologically, there is no real bias in either column through most of the matches from 1969 through the Sampras era. However as I scroll down into the current era I am already seeing large blocks of Federer matches in the column of matches won exclusively through forcing plays. So that may be where the bias is: because I've done so many Federer matches. You can see it in my opening post of this thread: my list of Federer matches is the longest one. I'll get you more exact info on this. For now let me add: just like you, I don't see why the two styles (aggressive and conservative) necessarily have to even out as equally effective methods of winning matches. Theoretically it's possible that the aggressive style is in fact more effective; and theoretically the conservative style may be more effective. This is all really interesting, your breakdown of the AM's into UE's and Forcing Plays has opened up a whole other way of looking at this.