Both my girls have slept like angels from birth. Appropriate to their ages (eg 4 weeks old 5 hour blocks, DD2 is now 12 weeks old and sleeps 7-10 hour blocks generally). Once DD1 hit 6 months, it all went downhill. It was completely to do with her, not with the way she was put to sleep IMO (fed to sleep, or rocked, or hair stroked). I really think the majority is just luck. Having had one child who slept 11 hours without fail for probably 4 months, and then at one point was waking up 10+ times a night, I've been on both ends of it. Honestly, I fully expect DD2 to follow suit, I'm kind of just waiting for it. If she doesn't, great! But we aren't doing anything differently to what we did with DD1 - cosleeping, feeding to sleep etc.