It is what it is, everyone puts lights as "King", lights are important, no shit, but other factors come into play. Strain, grow method, nute selection, smart nute usage, environment and other nuisances are what makes for a successful grow.
I have had grows with top strains that something invariably will go wrong. From equipment failure, wrong nute mix at the wrong time, stupid mistakes and the like, we only strive to get it right.
Now I am speaking as a hobby grower, grow for my own meds and pleasure. So shit will happen.
My last few grows, three Critical Kush and 2 Blue cheese. I went out of town for a short holiday, came back to plants that were 7 weeks of veg and 5 weeks into 12/12 and were cooked, equipment failure. Could not even make oil from them, so into the compost bin they went. First time use of the 315W was to be a 315W/400W HPS vert grow but seed got lost in the mail, so ended up using two freebie seeds, Super Citrus Haze and on off brand WW. Since I did not have enough plants to do a proper vert, I ran a two plant horizontal with the 315 and a SS400 LED, rotating plants regularly. Pulled 15 zips of smokable bud. Then was the G13 Haze + 1 CK vert grow, CK was fucked, never produced, but I got 24.5 zips smokable bud of the G13 Haze, 1 + GPW. This was followed by this past falls grow of the LSD, 5 plant vert and only turned 17+ of smokable bud. Am in the winter 18 grow now, yield is not expected to be that great because I was not able to get in the veg time. But it is what it is. So for me I grow enough for my needs and if I have leftovers at the next harvest, that leftovers go to a group a Vet's with PTSD. They also get any clones I may have extra and advice on their grows.
As I stated above, everything that happens is based on Strain, LIghting, Method, Your Grow Environment, Nutes and there proper usage. Oh yeah, and grow experience, the more you do something the better you get.
I love growing my own meds and recreation, it is a soothing hobby for this old man.
GR