When it comes to tabletop wargaming, you can have a masterful grasp of tactics and know your units' moves inside & out & sideways. You can compose your army list so that it could take on you if you were to physically climb on the table and square off against your miniatures. You could have your minitures painted so well it could cause a member of Games-Workshop's 'eavy metal team to weep... and all of that means less than a squirt of piss once the dice start rolling.
Especially in a game like Warhammer 40K, the ups and downs on the battlefield can be woven into a sweet narrative to bring your army to life or give dimension to a campaign. Dice rolling can really ruin that narrative unless you don't mind your armys' constant story being something told like this: "AHHHHHH!!!! Omg I've never seen the enemy do that! ACK! Not in the face, not in the FACE!!! arrrgh...."
As rarely as I play, that is the story told by any and all of my minitaure armies. If I sound bitter at all that is completely not the case. 20+ years ago when my hormones were in flux and I still had hair, I might have been upset by my persistant lack of good battlefield fortune. Now it's just the way it goes. The fun is in hanging out and seeing a beautiful battlefield turn proverbially red with fictional blood and carnage.
I played my first game of 5th edition Warhammer 40K last night; my Space Wolves vs. Chaos Space Marines. Somehow, SOMEHOW my boys pulled out a draw for me even though I failed them utterly, dropping the ball on every assault, armor save and reserve roll I was called to make. Absolutley nothing went my way, and still my boys pulled out a draw. A testament to the brilliance behind the new rules, or a statement about the kick-ass-ness of the Space Wolves, I don't know. Fun? Absolutely!