I tend to go about scheduling a little differently.
First (if their ranking is high enough) they will automatically play all four slams, and all nine masters series (remember I only play the men's version)
Then they need at least 5 more good tournaments (for their ranking) so I will play either one or both weeks before the Australian Open, then either one or two events between Oz and the two US IMS events. Maybe one extra clay event before the 3 IMS, then one grass warm up before Wimbledon (UK Open).
One more warm up before Cinci/Montreal/US Open, then either one or two more events before the final two masters series.
I usually try to keep a week off between most of the events they play if possible.
So my guys play 20-23 events a year once they rank in the top 100.
For my user character, he plays only every 3-4 weeks for the first year (usually less since I tend to get him injured by overtraining lol) then slowly moves into the top level by the middle / end of year 2.
EDIT: In real life, it varies between about 18-20 (Fed and Nadal / Ivanovic and Henin (before she retired) up to 30-35 (Davydenko / Jankovic). Then you have the Williams sisters (and Sharapova) who play only about 12-14 events.