Talk to a RailFan - you will learn a LOT about Trains.

My suggestion is that even if its 100 WL in Sleeper, book it, you may even be upgraded to 3A as was my case. The train, especially 3A and 2A are mostly vacant and SL is used by local unreserved passengers especially from UBL to YPR. Elsewhere it's mostly vacant. I travelled from Dadar but I think it would work from other places as well as one of my co passenger boarded at DVG to YPR in Sleeper class and he had a waiting list of RLWL 29 in SL just before chart preperation but it got confirmed after the preperation of chart. You can also check the PNR of this train on 8 March where passengers traveling from Dadar to Tiruvannamalai got upgraded to 3A from SL ( Entry# 4250797 ). Hope this helps you.

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