In addition to diggers3's answer, I would add:

• Grand Slam (major) events are not ATP or WTA events - they are ITF events and are not subject to the ATP's or WTA's rules. All non-major tournaments for both men and women are now best of 3 set matches.

• Generally in tennis, when more is on the line (think $$) then best of 5 sets are played instead of best of 3. It is a more comprehensive test and ensures that one player (or doubles team) can outperform the other and not that one player was just "hot" or "cold" for a set or two.

• Other men's tournaments used to play best of 5 sets also - Masters Series tournaments and the season-end Masters Cup (now World Tour Finals) used to play the best of 5 sets format also but changed to best of 3 in recent years.

• Tennis, as sports go, tends to be very entrenched in tradition and doing something like changing men's grand slam matches from best of 5 sets to best of 3 would take a lot of convincing of those in authority to make that change. In recent years, many tennis journalists and media figures have suggested that the grand slam events have the men play best of 3 sets up until the second week (or QuarterFinals) - then switch to best of 5 beyond that.

• As far as having the women play best of 5 sets like the men - I do not think that would be a good idea and would only contribute further to player injury and fatigue. I think you would end up seeing more retirements and walkover results than you do now. If anything, I think the men should switch to best of 3 before women change to best of 5.

In addition to diggers3's answer, I would add:

• Grand Slam (major) events are not ATP or WTA events - they are ITF events and are not subject to the ATP's or WTA's rules. All non-major tournaments for both men and women are now best of 3 sets matches.

• Generally in tennis, when more is on the line (think $$) then best of 5 sets are played instead of best of 3. It is a more comprehensive test and ensures that one player (or doubles team) can outperform the other and not that one player was just "hot" or "cold" for a set or two.

• Other men's tournaments used to play best of 5 sets also - Masters Series tournaments and the season-end Masters Cup (now World Tour Finals) used to play the best of 5 sets format also but changed to best of 3 in recent years.

• Tennis, as sports go, tends to be very entrenched in tradition and doing something like changing men's grand slam matches from best of 5 sets to best of 3 would take a lot of convincing of those in authority to make that change. In recent years, many tennis journalists and media figures have suggested that the grand slam events have the men play best of 3 sets up until the second week (or QuarterFinals) - then switch to best of 5 beyond that.

• As far as having the women play best of 5 sets like the men - I do not think that would be a good idea and would only contribute further to player injury and fatigue. I think you would end up seeing more retirements and walkover results than you do now. If anything, I think the men should switch to best of 3 before women change to best of 5.