Here's how things will work.
Winner of each group will advance to semifinals. Here is out that is determined:
1-Best record...if tied then
2-Head 2 Head...if tied then
3-Best percentage of sets won...if tied then
4-Best percentage of games won...if tied then
5-Best ranking...if tied then
6-Points earned from Grand Slams...if tied then
The final spot will be compared with the second place winner of each group using the above format except the head to head, as they have not played each other.
Semifinals Format will be
RED GROUP WINNER vs. SECOND PLACE QUALIFIER
BLUE GROUP WINNER VS. GREEN GROUP WINNER