Why GNWL is much better
GNWL draws from the general quota — hundreds of seats with regular cancellations throughout the 60-day booking window. TQWL is in the Tatkal quota, booked only 1 day before travel. Tatkal passengers have urgent travel needs and almost never cancel.
Confirmation probability comparison
GNWL 1-5: 88-95%. GNWL 6-15: 68-88%. GNWL 16-30: 38-68%. TQWL 1: 15-25%. TQWL 2: 5-15%. TQWL 3+: under 5%.
When would you have TQWL?
TQWL appears when you book a Tatkal ticket but the Tatkal quota was already full. Even TQWL 1 is riskier than GNWL 50 in most cases.
What to do
GNWL below 30: track and wait, real chance of confirmation. GNWL above 50: book a backup. TQWL any number: book a backup immediately — the wait is almost always futile.