"A fish lost because the hook pulls out or because the fish gets into a snag is something that can't be helped. Fish lost because of knot failure is a result of poor angling."
There are no 'strong' knots - no matter how well-tied and reliable a knot is, it's still a weak link in the tackle.
Unfortunately, even in the simplest rig you need at least one knot - to tie the hook on - so we're stuck with them. But by choosing the right knot for the job, tying it correctly and avoiding 'granny knots' you can cut your losses.
Two of the commonest ways in which knots fail are when the knot slips and comes undone and when the line breaks next to the knot as it is put under pressure. These can have several causes.
Knots are the weak links in your tackle but there is no need to make
them any worse by tying them badly. Make sure each knot is secure.
Tying knots with fine line on the river bank can be quite fiddly. It is a good idea to practise at home using thick line. Tying small spade end hooks to fine line also requires dexterity especially when your fingers are numb. Tie a stock of them in the comfort of your home and store them in packets or on winder boards, making a note of hook size, line strength and length and when they were tied.
If you have trouble tying Spade End Hooks, then try using a Hook Tyer.