The stats required are available at such sites as http://www.atpworldtour.com although the figure for second serve accuracy isn't generally listed and has to be derived from other stats, such as the number of double faults.
I've taken full tournament figures for players that progressed to the later stages of various tournaments so far in 2013 and others of general interest. The smallish sample sizes should be enough to catch the general trend, but would need further data collection or heavy regressing for the actual figures to carry greater authority.
Likelihood of Winning A Service Point Using Either A Conventional or Aggressive Strategy.
|Player/Surface.||Fast/Slower Serve.||Two Fast Serves.||% Advantage For Conventional Strategy.|
Every player I've looked at would have been better off using the conventional fast/slower service strategy, assuming that the stats they displayed in the various tournaments were repeatable and typical of their true abilities. Tennis players, it seems, know exactly what they are doing...at the start of the point at least.