Do easy mode, +4 tiles are abundant there.
Those tiles are virtually nonexistent in hard modes.
Originally Posted by mattp169
herby i find it to be the exact opposite at times. It is purely random how many and of what you get in each level lab
I've found them to be more common in easy than in hard. My guess is that they change the odds on each of the 3 difficulties. But hey a guy can wish that the +4 moves was more common on hard