Firstly if u r nt here for predicting pnr's then plz avoid it nobody will force u to predict pnr. get into the forum and do scientific discussion.
pnr prediction is not just blind shot but is based on scientific rule of how tkts get confirm in railways. there is a procedure which is followed in ticket clearance. and based on that predictions r made. some guys r doing really gud in pnr prediction. with gud accurate percentage.