Thread:Double Slap/@comment-3017217-20160219192338/@comment-4091261-20160220004415

Nice, you did a lot better. I think the minion focus came alongside the changes to focus against ranged champions. Beforehand, the minions only within your own range would aid you if you were being attacked. The issue with this is that long range autoattacking champions would rarely ever get minion aggro on them. But now even champions with a long range would get attacked by enemy minions around them if they attacked the enemy. Riot Reinbloom's post discusses this in detail.

I don't thinks this directly affected minion focus, but I recall around that time, that minions retained their aggro a lot longer--especially when charging at a minion wave with no minions around you. So I'm pretty sure that with that change came changes to the duration of minion aggro--even if it wasn't explicitly stated.