San Diego is an "all-purpose" court, but sometimes, when you're scheduled for trial, your particular judge is too busy, so you get bounced to a new judge for trial.
San Diego's local rules -- Rule 2.1.3 -- says that in such settings, your "all-purpose" judge magically turns into a "master calendar" judge, so you've got to make any peremptory challenges immediately.
The Court of Appeal holds that Rule 2.1.3 is too cute by half, and impermissibly conflicts with CCP 170.6.
So San Diego will have to try a different way to get its trials assigned to open courtrooms. One that's both consistent with CCP 170.6 and yet lets litigants timely challenge judges if they want.
POSTSCRIPT - A (very informed) reader tells me that San Diego has already dealt with this problem; indeed, did so last month, before Court of Appeal published Lorch. It created a master calendar judge (the supervising judge), and let all-purpose judges assign the case to the master calendar judge if the case is ready for trial but the all-purpose judge isn't ready. Voila! Problem solved. (Or seems to solve it as far as I can see; this solution seems cute but not 150% cute.)