I fot through four 1st strings in a day, and wonder if there is anything obvious that I might be doing wrong? I restrung my guitar with those dreadful D'Addario things, and the following say the first string broke close to the bridge. I wasn't thrashing it at all, and there seem to be no rough edges on the saddles. I therefore changed the string with one of my quickly dwindling stock of spares, and that broke right by the tuner, as did the next one I tried. The next time was successful, and has been in place for, oh, 36 hours now.
I didn't overtighten the string - just tuned it to pitch (perhaps just a little over) and stretched it and re-tuned a few times, but it was as if the string was cutting in to itself a bit too much.
It had never happended before.