CTLR INVOLVED IN LTSS DUE TO OVERLAPPING DATA TAGS.

Narrative

ACR X SCHEDULED FLT INTO LGA WAS AT FL260 AND DSNDED TO FL210. BECAUSE OF THE WAY THE SECTOR IS SET WE MUST BLEND LOW ALT DEP TFC FROM THE WASHINGTON METRO AREA WITH TFC MUCH FASTER AT A HIGHER CRUISE ALT. BECAUSE OF THE POOR PROCS THAT EXIST EXCESSIVE COORD IS REQUIRED FOR THE SEQUENCING OF THESE ACFT. I WAS INVOLVED IN COORDINATING OTHER TFC AND I NOTICED ACR X APCHING SECTOR BOUNDARY. I ATTEMPTED TO MAKE A POINT OUT. I THEN NOTICED THE DATA TAG CONFLICTING WITH ANOTHER ACFT. THE DATA TAG WAS NOT READABLE BECAUSE IT WAS OVERLAPPING. I COULD NOT TAKE IMMEDIATE EVASIVE ACTION BECAUSE I COULD NOT READ THE DATA TAG OF THE OTHER ACFT. I DID NOT KNOW WHETHER TO CLB OR DSND MY TFC. I TRIED REPEATEDLY TO OFFSET THE DATA TAG BUT IT WOULD NOT WORK. FINALLY WHEN I WAS ABLE TO OFFSET IT I NOTICED THE ACFT WERE AT THE SAME ALT. I IMMEDIATELY DSNDED ACR X. ACR X WAS TCASII EQUIPPED AND IT APPEARED TO WORK. ACR X RPTED A CONFLICT AND WAS TAKING EVASIVE ACTION IN A DSCNT AT THE SAME TIME I WAS ISSUING THE CLRNC. THE ACFT CAME WITHIN 3 1/2 MI. CONTRIBUTING FACTORS: THE PROCS AT THIS SECTOR ARE VERY BAD. PLEASE HELP US DO SOMETHING. THIS IS THE THIRD ERROR OF THIS EXACT SAME TYPE AT THIS SECTOR WITHIN THE LAST 33 DAYS AND THE SECOND ONE THIS WK; ALL AMONG SEASONED CTLRS.