My trust in our train system is such that, if I have a London trip, the very first thing I do in the morning is see whether the trains are running (on time, or at all).
Not that that can't change at any point before my train. Or while I am on it.
But, fingers crossed...
22 minutes late.
The projected journey time was 40 minutes, so on that basis, we were delayed by (just) over 50% of the total journey time.
Not a big deal, but this is in part why I plan :)