Uh……that is the old way. I really don’t think it is accurate. 100 feet of solid 10.a jamming is going to feel harder than the single move of 10.a. Therefore newer climbs are taking into account the length of the climb. I prefer this style of grading because its gives more of an accurate view of what it feels like to lead without falling from ground to chains.
There is a climb at my local crag called “The Crumbing”. The FA gave the grade to be 5.12a. He has put up over 60 climbs in his life and knows what 12.a feels like.
The route has no 5.12a move on it. It starts with a V3 moves just to get your feet off the ground then another 3 to 4 hard moves to get to a good hold. He calls these opening moves about 11+. Then another 17 to 18 more moves of solid 11.a/b moves with an 11.c overhanging finish. The entire climb overhangs about 12 – 15 feet.
He feels if you lead it from ground to chains without falling, it would be 12.a.
I agree.