Just before charting, I checked the availability in this train from Mumbai to Madgaon in 1AC and 2AC. Tatkal was not available, General Quota had WL, no berths in Lower Berth Quota, no berths available in other quotas. On charting the system shows AVAILABLE 15 in 2 AC and AVAILABLE 4 IN 1AC. Now where do these berths come from? I can understand short distance availabilities due to passengers not booking all berths between 1st and last station. No chance however for auto upgradation since system will not auto upgrade from lower to upper class when berths are available in lower class. No question of extra coach being attached as this is already a 24 coach train.
I can continue to check...
more... the pattern for few more days to see if its a regular phenomenon.