My understanding regarding lines separating LBT and DBT are as follows:
- Fed: the lines are in LBT. A fielder in LBT is not considered to be in DBT until both feet have touched in DBT. Once in DBT with both feet, the fielder is not considered back in LBT until both feet have touched in LBT.
- NCAA: The line is in LBT, and the fielder is considered in DBT anytime one foot steps over the line. He is back in LBT when no foot is touching over the line.
- OBR: The line is in DBT, and the fielder is considered in DBT any time his foot is touching or over the line. He is back in LBT when no foot is touching on or over the line.
I hope I've recalled this correctly.
I took the effort to look it up once, but don't intend to again.
That's how I understand it to be, and that's how it would be called by me if a decision had to be made regarding a fielder making a catch near such a line.
Amazingly, a Fed player moving from LBT toward DBT could actually cross the line by stepping over the line with one foot while the other is in the air (thus no part of his body in LBT), make the catch, and then reset a foot into LBT and continue to play with never being considered as leaving LBT. Since he was never in DBT with both feet, he was considered to be in LBT.
Just my opinion,
Freix