Scripting

To achieve this you would need some pretty fancy SQL, the easiest way I have done it is to set all tickets ending 1,4,7 to analyst A 2,5,8 to Analyst B etc, but 3 does not go into 10 in this instance. 

To round robin assign, you would need to find a field value that is available from the database for every ticket and then get a ticket rule to switch from one to the other, not impossible, but pretty time consuming to setup.

So here's my thinking to set this up, first record the ID's of your analyst so we can use the in the field HD_TICKET.OWNER_ID, lets say they are ID's 59, 72 and 137.

Next I suggest you use a default value in a custom field as they are written in every ticket, so let's use custom field 15 (HD_TICKET.CUSTOM_FIELD_VALUE14) in the database, edit your queue and add in a default value of the first analyst ID (59)

Now we need to build a ticket rule that selects that default value.

You can find that data in HD_CUSTOM_FIELDS. I think you should find custom field 15 in the Queue you are using and find out what ID that field is in, so you should find your default value of 59 in the field HD_CUSTOM_FIELD.DEFAULT so record HD_CUSTOM_FIELD.ID for the line that is the custom field in your queue with your default value written.

So now build your custom ticket rule to update the field HD_CUSTOM_FIELD.DEFAULT with an update CASE statement that goes

HD_CUSTOM_FIELD.DEFAULT = CASE 

                WHEN HD_CUSTOM_FIELD.DEFAULT = '59' THEN '72'

                WHEN HD_CUSTOM_FIELD.DEFAULT = '72' THEN '137'

                WHEN HD_CUSTOM_FIELD.DEFAULT = '137' THEN '59'

END

WHERE HD_CUSTOM_FIELD.ID = (whatever ID we recorded earlier)

That will provide the sequential round robin update of your analyst ID into the default custom field value.

You then need to build a simple ticket rule to set the analyst ID HD_TICKET.OWNER_ID with the value in HD_CUSTOM_FIELD.DEFAULT

Run these ticket rules one after the other before any other ticket rule and on ticket save.

How does that sound??